mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-29 23:53:32 +00:00
4066 lines
95 KiB
C
4066 lines
95 KiB
C
/*
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* Simplified MAC Kernel (smack) security module
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*
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* This file contains the smack hook function implementations.
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*
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* Authors:
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* Casey Schaufler <casey@schaufler-ca.com>
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* Jarkko Sakkinen <jarkko.sakkinen@intel.com>
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*
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* Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
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* Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
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* Paul Moore <paul@paul-moore.com>
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* Copyright (C) 2010 Nokia Corporation
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* Copyright (C) 2011 Intel Corporation.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2,
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* as published by the Free Software Foundation.
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*/
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#include <linux/xattr.h>
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#include <linux/pagemap.h>
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#include <linux/mount.h>
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#include <linux/stat.h>
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#include <linux/kd.h>
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#include <asm/ioctls.h>
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#include <linux/ip.h>
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#include <linux/tcp.h>
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#include <linux/udp.h>
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#include <linux/dccp.h>
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#include <linux/slab.h>
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#include <linux/mutex.h>
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#include <linux/pipe_fs_i.h>
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#include <net/cipso_ipv4.h>
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#include <net/ip.h>
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#include <net/ipv6.h>
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#include <linux/audit.h>
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#include <linux/magic.h>
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#include <linux/dcache.h>
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#include <linux/personality.h>
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#include <linux/msg.h>
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#include <linux/shm.h>
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#include <linux/binfmts.h>
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#include "smack.h"
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#define task_security(task) (task_cred_xxx((task), security))
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#define TRANS_TRUE "TRUE"
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#define TRANS_TRUE_SIZE 4
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#define SMK_CONNECTING 0
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#define SMK_RECEIVING 1
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#define SMK_SENDING 2
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LIST_HEAD(smk_ipv6_port_list);
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/**
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* smk_fetch - Fetch the smack label from a file.
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* @ip: a pointer to the inode
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* @dp: a pointer to the dentry
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*
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* Returns a pointer to the master list entry for the Smack label
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* or NULL if there was no label to fetch.
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*/
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static struct smack_known *smk_fetch(const char *name, struct inode *ip,
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struct dentry *dp)
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{
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int rc;
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char *buffer;
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struct smack_known *skp = NULL;
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if (ip->i_op->getxattr == NULL)
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return NULL;
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buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL);
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if (buffer == NULL)
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return NULL;
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rc = ip->i_op->getxattr(dp, name, buffer, SMK_LONGLABEL);
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if (rc > 0)
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skp = smk_import_entry(buffer, rc);
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kfree(buffer);
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return skp;
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}
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/**
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* new_inode_smack - allocate an inode security blob
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* @smack: a pointer to the Smack label to use in the blob
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*
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* Returns the new blob or NULL if there's no memory available
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*/
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struct inode_smack *new_inode_smack(char *smack)
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{
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struct inode_smack *isp;
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isp = kzalloc(sizeof(struct inode_smack), GFP_NOFS);
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if (isp == NULL)
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return NULL;
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isp->smk_inode = smack;
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isp->smk_flags = 0;
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mutex_init(&isp->smk_lock);
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return isp;
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}
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/**
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* new_task_smack - allocate a task security blob
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* @smack: a pointer to the Smack label to use in the blob
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*
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* Returns the new blob or NULL if there's no memory available
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*/
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static struct task_smack *new_task_smack(struct smack_known *task,
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struct smack_known *forked, gfp_t gfp)
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{
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struct task_smack *tsp;
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tsp = kzalloc(sizeof(struct task_smack), gfp);
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if (tsp == NULL)
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return NULL;
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tsp->smk_task = task;
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tsp->smk_forked = forked;
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INIT_LIST_HEAD(&tsp->smk_rules);
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mutex_init(&tsp->smk_rules_lock);
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return tsp;
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}
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/**
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* smk_copy_rules - copy a rule set
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* @nhead - new rules header pointer
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* @ohead - old rules header pointer
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*
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* Returns 0 on success, -ENOMEM on error
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*/
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static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
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gfp_t gfp)
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{
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struct smack_rule *nrp;
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struct smack_rule *orp;
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int rc = 0;
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INIT_LIST_HEAD(nhead);
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list_for_each_entry_rcu(orp, ohead, list) {
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nrp = kzalloc(sizeof(struct smack_rule), gfp);
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if (nrp == NULL) {
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rc = -ENOMEM;
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break;
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}
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*nrp = *orp;
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list_add_rcu(&nrp->list, nhead);
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}
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return rc;
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}
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/**
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* smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_*
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* @mode - input mode in form of PTRACE_MODE_*
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*
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* Returns a converted MAY_* mode usable by smack rules
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*/
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static inline unsigned int smk_ptrace_mode(unsigned int mode)
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{
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switch (mode) {
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case PTRACE_MODE_READ:
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return MAY_READ;
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case PTRACE_MODE_ATTACH:
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return MAY_READWRITE;
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}
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return 0;
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}
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/**
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* smk_ptrace_rule_check - helper for ptrace access
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* @tracer: tracer process
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* @tracee_label: label of the process that's about to be traced,
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* the pointer must originate from smack structures
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* @mode: ptrace attachment mode (PTRACE_MODE_*)
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* @func: name of the function that called us, used for audit
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*
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* Returns 0 on access granted, -error on error
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*/
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static int smk_ptrace_rule_check(struct task_struct *tracer, char *tracee_label,
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unsigned int mode, const char *func)
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{
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int rc;
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struct smk_audit_info ad, *saip = NULL;
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struct task_smack *tsp;
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struct smack_known *skp;
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if ((mode & PTRACE_MODE_NOAUDIT) == 0) {
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smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK);
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smk_ad_setfield_u_tsk(&ad, tracer);
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saip = &ad;
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}
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tsp = task_security(tracer);
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skp = smk_of_task(tsp);
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if ((mode & PTRACE_MODE_ATTACH) &&
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(smack_ptrace_rule == SMACK_PTRACE_EXACT ||
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smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)) {
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if (skp->smk_known == tracee_label)
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rc = 0;
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else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)
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rc = -EACCES;
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else if (capable(CAP_SYS_PTRACE))
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rc = 0;
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else
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rc = -EACCES;
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if (saip)
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smack_log(skp->smk_known, tracee_label, 0, rc, saip);
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return rc;
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}
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/* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */
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rc = smk_tskacc(tsp, tracee_label, smk_ptrace_mode(mode), saip);
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return rc;
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}
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/*
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* LSM hooks.
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* We he, that is fun!
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*/
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/**
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* smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
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* @ctp: child task pointer
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* @mode: ptrace attachment mode (PTRACE_MODE_*)
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*
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* Returns 0 if access is OK, an error code otherwise
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*
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* Do the capability checks.
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*/
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static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
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{
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int rc;
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struct smack_known *skp;
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rc = cap_ptrace_access_check(ctp, mode);
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if (rc != 0)
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return rc;
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skp = smk_of_task(task_security(ctp));
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rc = smk_ptrace_rule_check(current, skp->smk_known, mode, __func__);
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return rc;
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}
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/**
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* smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
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* @ptp: parent task pointer
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*
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* Returns 0 if access is OK, an error code otherwise
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*
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* Do the capability checks, and require PTRACE_MODE_ATTACH.
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*/
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static int smack_ptrace_traceme(struct task_struct *ptp)
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{
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int rc;
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struct smack_known *skp;
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rc = cap_ptrace_traceme(ptp);
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if (rc != 0)
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return rc;
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skp = smk_of_task(current_security());
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rc = smk_ptrace_rule_check(ptp, skp->smk_known,
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PTRACE_MODE_ATTACH, __func__);
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return rc;
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}
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/**
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* smack_syslog - Smack approval on syslog
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* @type: message type
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*
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* Returns 0 on success, error code otherwise.
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*/
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static int smack_syslog(int typefrom_file)
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{
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int rc = 0;
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struct smack_known *skp = smk_of_current();
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if (smack_privileged(CAP_MAC_OVERRIDE))
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return 0;
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if (smack_syslog_label != NULL && smack_syslog_label != skp)
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rc = -EACCES;
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return rc;
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}
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/*
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* Superblock Hooks.
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*/
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/**
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* smack_sb_alloc_security - allocate a superblock blob
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* @sb: the superblock getting the blob
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*
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* Returns 0 on success or -ENOMEM on error.
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*/
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static int smack_sb_alloc_security(struct super_block *sb)
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{
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struct superblock_smack *sbsp;
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sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
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if (sbsp == NULL)
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return -ENOMEM;
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sbsp->smk_root = smack_known_floor.smk_known;
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sbsp->smk_default = smack_known_floor.smk_known;
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sbsp->smk_floor = smack_known_floor.smk_known;
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sbsp->smk_hat = smack_known_hat.smk_known;
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/*
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* smk_initialized will be zero from kzalloc.
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*/
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sb->s_security = sbsp;
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return 0;
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}
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/**
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* smack_sb_free_security - free a superblock blob
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* @sb: the superblock getting the blob
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*
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*/
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static void smack_sb_free_security(struct super_block *sb)
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{
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kfree(sb->s_security);
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sb->s_security = NULL;
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}
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/**
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* smack_sb_copy_data - copy mount options data for processing
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* @orig: where to start
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* @smackopts: mount options string
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*
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* Returns 0 on success or -ENOMEM on error.
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*
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* Copy the Smack specific mount options out of the mount
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* options list.
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*/
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static int smack_sb_copy_data(char *orig, char *smackopts)
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{
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char *cp, *commap, *otheropts, *dp;
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otheropts = (char *)get_zeroed_page(GFP_KERNEL);
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if (otheropts == NULL)
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return -ENOMEM;
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for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
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if (strstr(cp, SMK_FSDEFAULT) == cp)
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dp = smackopts;
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else if (strstr(cp, SMK_FSFLOOR) == cp)
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dp = smackopts;
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else if (strstr(cp, SMK_FSHAT) == cp)
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dp = smackopts;
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else if (strstr(cp, SMK_FSROOT) == cp)
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dp = smackopts;
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else if (strstr(cp, SMK_FSTRANS) == cp)
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dp = smackopts;
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else
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dp = otheropts;
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commap = strchr(cp, ',');
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if (commap != NULL)
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*commap = '\0';
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if (*dp != '\0')
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strcat(dp, ",");
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strcat(dp, cp);
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}
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strcpy(orig, otheropts);
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free_page((unsigned long)otheropts);
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return 0;
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}
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/**
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* smack_sb_kern_mount - Smack specific mount processing
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* @sb: the file system superblock
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* @flags: the mount flags
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* @data: the smack mount options
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*
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* Returns 0 on success, an error code on failure
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*/
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static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
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{
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struct dentry *root = sb->s_root;
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struct inode *inode = root->d_inode;
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struct superblock_smack *sp = sb->s_security;
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struct inode_smack *isp;
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struct smack_known *skp;
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char *op;
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char *commap;
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char *nsp;
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int transmute = 0;
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int specified = 0;
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if (sp->smk_initialized)
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return 0;
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sp->smk_initialized = 1;
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for (op = data; op != NULL; op = commap) {
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commap = strchr(op, ',');
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if (commap != NULL)
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*commap++ = '\0';
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if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
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op += strlen(SMK_FSHAT);
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nsp = smk_import(op, 0);
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if (nsp != NULL) {
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sp->smk_hat = nsp;
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specified = 1;
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}
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} else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
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op += strlen(SMK_FSFLOOR);
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nsp = smk_import(op, 0);
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if (nsp != NULL) {
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sp->smk_floor = nsp;
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specified = 1;
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}
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} else if (strncmp(op, SMK_FSDEFAULT,
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strlen(SMK_FSDEFAULT)) == 0) {
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op += strlen(SMK_FSDEFAULT);
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nsp = smk_import(op, 0);
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if (nsp != NULL) {
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sp->smk_default = nsp;
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specified = 1;
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}
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} else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
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op += strlen(SMK_FSROOT);
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nsp = smk_import(op, 0);
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if (nsp != NULL) {
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sp->smk_root = nsp;
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specified = 1;
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}
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} else if (strncmp(op, SMK_FSTRANS, strlen(SMK_FSTRANS)) == 0) {
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op += strlen(SMK_FSTRANS);
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nsp = smk_import(op, 0);
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if (nsp != NULL) {
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sp->smk_root = nsp;
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transmute = 1;
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specified = 1;
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}
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}
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}
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if (!smack_privileged(CAP_MAC_ADMIN)) {
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/*
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* Unprivileged mounts don't get to specify Smack values.
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*/
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if (specified)
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return -EPERM;
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/*
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* Unprivileged mounts get root and default from the caller.
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*/
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skp = smk_of_current();
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sp->smk_root = skp->smk_known;
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sp->smk_default = skp->smk_known;
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}
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/*
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* Initialize the root inode.
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*/
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isp = inode->i_security;
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if (isp == NULL) {
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isp = new_inode_smack(sp->smk_root);
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if (isp == NULL)
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return -ENOMEM;
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inode->i_security = isp;
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} else
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isp->smk_inode = sp->smk_root;
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if (transmute)
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isp->smk_flags |= SMK_INODE_TRANSMUTE;
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return 0;
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}
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/**
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* smack_sb_statfs - Smack check on statfs
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* @dentry: identifies the file system in question
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*
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* Returns 0 if current can read the floor of the filesystem,
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* and error code otherwise
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*/
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static int smack_sb_statfs(struct dentry *dentry)
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{
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struct superblock_smack *sbp = dentry->d_sb->s_security;
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int rc;
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struct smk_audit_info ad;
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smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
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smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
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rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
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return rc;
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}
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|
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/*
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* BPRM hooks
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*/
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/**
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* smack_bprm_set_creds - set creds for exec
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* @bprm: the exec information
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*
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* Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise
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*/
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static int smack_bprm_set_creds(struct linux_binprm *bprm)
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{
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struct inode *inode = file_inode(bprm->file);
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struct task_smack *bsp = bprm->cred->security;
|
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struct inode_smack *isp;
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int rc;
|
|
|
|
rc = cap_bprm_set_creds(bprm);
|
|
if (rc != 0)
|
|
return rc;
|
|
|
|
if (bprm->cred_prepared)
|
|
return 0;
|
|
|
|
isp = inode->i_security;
|
|
if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
|
|
return 0;
|
|
|
|
if (bprm->unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
|
|
struct task_struct *tracer;
|
|
rc = 0;
|
|
|
|
rcu_read_lock();
|
|
tracer = ptrace_parent(current);
|
|
if (likely(tracer != NULL))
|
|
rc = smk_ptrace_rule_check(tracer,
|
|
isp->smk_task->smk_known,
|
|
PTRACE_MODE_ATTACH,
|
|
__func__);
|
|
rcu_read_unlock();
|
|
|
|
if (rc != 0)
|
|
return rc;
|
|
} else if (bprm->unsafe)
|
|
return -EPERM;
|
|
|
|
bsp->smk_task = isp->smk_task;
|
|
bprm->per_clear |= PER_CLEAR_ON_SETID;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_bprm_committing_creds - Prepare to install the new credentials
|
|
* from bprm.
|
|
*
|
|
* @bprm: binprm for exec
|
|
*/
|
|
static void smack_bprm_committing_creds(struct linux_binprm *bprm)
|
|
{
|
|
struct task_smack *bsp = bprm->cred->security;
|
|
|
|
if (bsp->smk_task != bsp->smk_forked)
|
|
current->pdeath_signal = 0;
|
|
}
|
|
|
|
/**
|
|
* smack_bprm_secureexec - Return the decision to use secureexec.
|
|
* @bprm: binprm for exec
|
|
*
|
|
* Returns 0 on success.
|
|
*/
|
|
static int smack_bprm_secureexec(struct linux_binprm *bprm)
|
|
{
|
|
struct task_smack *tsp = current_security();
|
|
int ret = cap_bprm_secureexec(bprm);
|
|
|
|
if (!ret && (tsp->smk_task != tsp->smk_forked))
|
|
ret = 1;
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Inode hooks
|
|
*/
|
|
|
|
/**
|
|
* smack_inode_alloc_security - allocate an inode blob
|
|
* @inode: the inode in need of a blob
|
|
*
|
|
* Returns 0 if it gets a blob, -ENOMEM otherwise
|
|
*/
|
|
static int smack_inode_alloc_security(struct inode *inode)
|
|
{
|
|
struct smack_known *skp = smk_of_current();
|
|
|
|
inode->i_security = new_inode_smack(skp->smk_known);
|
|
if (inode->i_security == NULL)
|
|
return -ENOMEM;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_inode_free_security - free an inode blob
|
|
* @inode: the inode with a blob
|
|
*
|
|
* Clears the blob pointer in inode
|
|
*/
|
|
static void smack_inode_free_security(struct inode *inode)
|
|
{
|
|
kfree(inode->i_security);
|
|
inode->i_security = NULL;
|
|
}
|
|
|
|
/**
|
|
* smack_inode_init_security - copy out the smack from an inode
|
|
* @inode: the inode
|
|
* @dir: unused
|
|
* @qstr: unused
|
|
* @name: where to put the attribute name
|
|
* @value: where to put the attribute value
|
|
* @len: where to put the length of the attribute
|
|
*
|
|
* Returns 0 if it all works out, -ENOMEM if there's no memory
|
|
*/
|
|
static int smack_inode_init_security(struct inode *inode, struct inode *dir,
|
|
const struct qstr *qstr, const char **name,
|
|
void **value, size_t *len)
|
|
{
|
|
struct inode_smack *issp = inode->i_security;
|
|
struct smack_known *skp = smk_of_current();
|
|
char *isp = smk_of_inode(inode);
|
|
char *dsp = smk_of_inode(dir);
|
|
int may;
|
|
|
|
if (name)
|
|
*name = XATTR_SMACK_SUFFIX;
|
|
|
|
if (value) {
|
|
rcu_read_lock();
|
|
may = smk_access_entry(skp->smk_known, dsp, &skp->smk_rules);
|
|
rcu_read_unlock();
|
|
|
|
/*
|
|
* If the access rule allows transmutation and
|
|
* the directory requests transmutation then
|
|
* by all means transmute.
|
|
* Mark the inode as changed.
|
|
*/
|
|
if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
|
|
smk_inode_transmutable(dir)) {
|
|
isp = dsp;
|
|
issp->smk_flags |= SMK_INODE_CHANGED;
|
|
}
|
|
|
|
*value = kstrdup(isp, GFP_NOFS);
|
|
if (*value == NULL)
|
|
return -ENOMEM;
|
|
}
|
|
|
|
if (len)
|
|
*len = strlen(isp) + 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_inode_link - Smack check on link
|
|
* @old_dentry: the existing object
|
|
* @dir: unused
|
|
* @new_dentry: the new object
|
|
*
|
|
* Returns 0 if access is permitted, an error code otherwise
|
|
*/
|
|
static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
|
|
struct dentry *new_dentry)
|
|
{
|
|
char *isp;
|
|
struct smk_audit_info ad;
|
|
int rc;
|
|
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
|
|
smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
|
|
|
|
isp = smk_of_inode(old_dentry->d_inode);
|
|
rc = smk_curacc(isp, MAY_WRITE, &ad);
|
|
|
|
if (rc == 0 && new_dentry->d_inode != NULL) {
|
|
isp = smk_of_inode(new_dentry->d_inode);
|
|
smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
|
|
rc = smk_curacc(isp, MAY_WRITE, &ad);
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_inode_unlink - Smack check on inode deletion
|
|
* @dir: containing directory object
|
|
* @dentry: file to unlink
|
|
*
|
|
* Returns 0 if current can write the containing directory
|
|
* and the object, error code otherwise
|
|
*/
|
|
static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
struct inode *ip = dentry->d_inode;
|
|
struct smk_audit_info ad;
|
|
int rc;
|
|
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
|
|
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
|
|
|
|
/*
|
|
* You need write access to the thing you're unlinking
|
|
*/
|
|
rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
|
|
if (rc == 0) {
|
|
/*
|
|
* You also need write access to the containing directory
|
|
*/
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
|
|
smk_ad_setfield_u_fs_inode(&ad, dir);
|
|
rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_inode_rmdir - Smack check on directory deletion
|
|
* @dir: containing directory object
|
|
* @dentry: directory to unlink
|
|
*
|
|
* Returns 0 if current can write the containing directory
|
|
* and the directory, error code otherwise
|
|
*/
|
|
static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
struct smk_audit_info ad;
|
|
int rc;
|
|
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
|
|
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
|
|
|
|
/*
|
|
* You need write access to the thing you're removing
|
|
*/
|
|
rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
|
|
if (rc == 0) {
|
|
/*
|
|
* You also need write access to the containing directory
|
|
*/
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
|
|
smk_ad_setfield_u_fs_inode(&ad, dir);
|
|
rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_inode_rename - Smack check on rename
|
|
* @old_inode: the old directory
|
|
* @old_dentry: unused
|
|
* @new_inode: the new directory
|
|
* @new_dentry: unused
|
|
*
|
|
* Read and write access is required on both the old and
|
|
* new directories.
|
|
*
|
|
* Returns 0 if access is permitted, an error code otherwise
|
|
*/
|
|
static int smack_inode_rename(struct inode *old_inode,
|
|
struct dentry *old_dentry,
|
|
struct inode *new_inode,
|
|
struct dentry *new_dentry)
|
|
{
|
|
int rc;
|
|
char *isp;
|
|
struct smk_audit_info ad;
|
|
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
|
|
smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
|
|
|
|
isp = smk_of_inode(old_dentry->d_inode);
|
|
rc = smk_curacc(isp, MAY_READWRITE, &ad);
|
|
|
|
if (rc == 0 && new_dentry->d_inode != NULL) {
|
|
isp = smk_of_inode(new_dentry->d_inode);
|
|
smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
|
|
rc = smk_curacc(isp, MAY_READWRITE, &ad);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_inode_permission - Smack version of permission()
|
|
* @inode: the inode in question
|
|
* @mask: the access requested
|
|
*
|
|
* This is the important Smack hook.
|
|
*
|
|
* Returns 0 if access is permitted, -EACCES otherwise
|
|
*/
|
|
static int smack_inode_permission(struct inode *inode, int mask)
|
|
{
|
|
struct smk_audit_info ad;
|
|
int no_block = mask & MAY_NOT_BLOCK;
|
|
|
|
mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
|
|
/*
|
|
* No permission to check. Existence test. Yup, it's there.
|
|
*/
|
|
if (mask == 0)
|
|
return 0;
|
|
|
|
/* May be droppable after audit */
|
|
if (no_block)
|
|
return -ECHILD;
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
|
|
smk_ad_setfield_u_fs_inode(&ad, inode);
|
|
return smk_curacc(smk_of_inode(inode), mask, &ad);
|
|
}
|
|
|
|
/**
|
|
* smack_inode_setattr - Smack check for setting attributes
|
|
* @dentry: the object
|
|
* @iattr: for the force flag
|
|
*
|
|
* Returns 0 if access is permitted, an error code otherwise
|
|
*/
|
|
static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
|
|
{
|
|
struct smk_audit_info ad;
|
|
/*
|
|
* Need to allow for clearing the setuid bit.
|
|
*/
|
|
if (iattr->ia_valid & ATTR_FORCE)
|
|
return 0;
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
|
|
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
|
|
|
|
return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
|
|
}
|
|
|
|
/**
|
|
* smack_inode_getattr - Smack check for getting attributes
|
|
* @mnt: unused
|
|
* @dentry: the object
|
|
*
|
|
* Returns 0 if access is permitted, an error code otherwise
|
|
*/
|
|
static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
|
|
{
|
|
struct smk_audit_info ad;
|
|
struct path path;
|
|
|
|
path.dentry = dentry;
|
|
path.mnt = mnt;
|
|
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
|
|
smk_ad_setfield_u_fs_path(&ad, path);
|
|
return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
|
|
}
|
|
|
|
/**
|
|
* smack_inode_setxattr - Smack check for setting xattrs
|
|
* @dentry: the object
|
|
* @name: name of the attribute
|
|
* @value: unused
|
|
* @size: unused
|
|
* @flags: unused
|
|
*
|
|
* This protects the Smack attribute explicitly.
|
|
*
|
|
* Returns 0 if access is permitted, an error code otherwise
|
|
*/
|
|
static int smack_inode_setxattr(struct dentry *dentry, const char *name,
|
|
const void *value, size_t size, int flags)
|
|
{
|
|
struct smk_audit_info ad;
|
|
struct smack_known *skp;
|
|
int check_priv = 0;
|
|
int check_import = 0;
|
|
int check_star = 0;
|
|
int rc = 0;
|
|
|
|
/*
|
|
* Check label validity here so import won't fail in post_setxattr
|
|
*/
|
|
if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
|
|
strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
|
|
strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
|
|
check_priv = 1;
|
|
check_import = 1;
|
|
} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
|
|
strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
|
|
check_priv = 1;
|
|
check_import = 1;
|
|
check_star = 1;
|
|
} else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
|
|
check_priv = 1;
|
|
if (size != TRANS_TRUE_SIZE ||
|
|
strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
|
|
rc = -EINVAL;
|
|
} else
|
|
rc = cap_inode_setxattr(dentry, name, value, size, flags);
|
|
|
|
if (check_priv && !smack_privileged(CAP_MAC_ADMIN))
|
|
rc = -EPERM;
|
|
|
|
if (rc == 0 && check_import) {
|
|
skp = smk_import_entry(value, size);
|
|
if (skp == NULL || (check_star &&
|
|
(skp == &smack_known_star || skp == &smack_known_web)))
|
|
rc = -EINVAL;
|
|
}
|
|
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
|
|
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
|
|
|
|
if (rc == 0)
|
|
rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_inode_post_setxattr - Apply the Smack update approved above
|
|
* @dentry: object
|
|
* @name: attribute name
|
|
* @value: attribute value
|
|
* @size: attribute size
|
|
* @flags: unused
|
|
*
|
|
* Set the pointer in the inode blob to the entry found
|
|
* in the master label list.
|
|
*/
|
|
static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
|
|
const void *value, size_t size, int flags)
|
|
{
|
|
struct smack_known *skp;
|
|
struct inode_smack *isp = dentry->d_inode->i_security;
|
|
|
|
if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
|
|
isp->smk_flags |= SMK_INODE_TRANSMUTE;
|
|
return;
|
|
}
|
|
|
|
if (strcmp(name, XATTR_NAME_SMACK) == 0) {
|
|
skp = smk_import_entry(value, size);
|
|
if (skp != NULL)
|
|
isp->smk_inode = skp->smk_known;
|
|
else
|
|
isp->smk_inode = smack_known_invalid.smk_known;
|
|
} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
|
|
skp = smk_import_entry(value, size);
|
|
if (skp != NULL)
|
|
isp->smk_task = skp;
|
|
else
|
|
isp->smk_task = &smack_known_invalid;
|
|
} else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
|
|
skp = smk_import_entry(value, size);
|
|
if (skp != NULL)
|
|
isp->smk_mmap = skp;
|
|
else
|
|
isp->smk_mmap = &smack_known_invalid;
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
/**
|
|
* smack_inode_getxattr - Smack check on getxattr
|
|
* @dentry: the object
|
|
* @name: unused
|
|
*
|
|
* Returns 0 if access is permitted, an error code otherwise
|
|
*/
|
|
static int smack_inode_getxattr(struct dentry *dentry, const char *name)
|
|
{
|
|
struct smk_audit_info ad;
|
|
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
|
|
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
|
|
|
|
return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
|
|
}
|
|
|
|
/**
|
|
* smack_inode_removexattr - Smack check on removexattr
|
|
* @dentry: the object
|
|
* @name: name of the attribute
|
|
*
|
|
* Removing the Smack attribute requires CAP_MAC_ADMIN
|
|
*
|
|
* Returns 0 if access is permitted, an error code otherwise
|
|
*/
|
|
static int smack_inode_removexattr(struct dentry *dentry, const char *name)
|
|
{
|
|
struct inode_smack *isp;
|
|
struct smk_audit_info ad;
|
|
int rc = 0;
|
|
|
|
if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
|
|
strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
|
|
strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
|
|
strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
|
|
strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
|
|
strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
|
|
if (!smack_privileged(CAP_MAC_ADMIN))
|
|
rc = -EPERM;
|
|
} else
|
|
rc = cap_inode_removexattr(dentry, name);
|
|
|
|
if (rc != 0)
|
|
return rc;
|
|
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
|
|
smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
|
|
|
|
rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
|
|
if (rc != 0)
|
|
return rc;
|
|
|
|
isp = dentry->d_inode->i_security;
|
|
/*
|
|
* Don't do anything special for these.
|
|
* XATTR_NAME_SMACKIPIN
|
|
* XATTR_NAME_SMACKIPOUT
|
|
* XATTR_NAME_SMACKEXEC
|
|
*/
|
|
if (strcmp(name, XATTR_NAME_SMACK) == 0)
|
|
isp->smk_task = NULL;
|
|
else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0)
|
|
isp->smk_mmap = NULL;
|
|
else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
|
|
isp->smk_flags &= ~SMK_INODE_TRANSMUTE;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_inode_getsecurity - get smack xattrs
|
|
* @inode: the object
|
|
* @name: attribute name
|
|
* @buffer: where to put the result
|
|
* @alloc: unused
|
|
*
|
|
* Returns the size of the attribute or an error code
|
|
*/
|
|
static int smack_inode_getsecurity(const struct inode *inode,
|
|
const char *name, void **buffer,
|
|
bool alloc)
|
|
{
|
|
struct socket_smack *ssp;
|
|
struct socket *sock;
|
|
struct super_block *sbp;
|
|
struct inode *ip = (struct inode *)inode;
|
|
char *isp;
|
|
int ilen;
|
|
int rc = 0;
|
|
|
|
if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
|
|
isp = smk_of_inode(inode);
|
|
ilen = strlen(isp) + 1;
|
|
*buffer = isp;
|
|
return ilen;
|
|
}
|
|
|
|
/*
|
|
* The rest of the Smack xattrs are only on sockets.
|
|
*/
|
|
sbp = ip->i_sb;
|
|
if (sbp->s_magic != SOCKFS_MAGIC)
|
|
return -EOPNOTSUPP;
|
|
|
|
sock = SOCKET_I(ip);
|
|
if (sock == NULL || sock->sk == NULL)
|
|
return -EOPNOTSUPP;
|
|
|
|
ssp = sock->sk->sk_security;
|
|
|
|
if (strcmp(name, XATTR_SMACK_IPIN) == 0)
|
|
isp = ssp->smk_in->smk_known;
|
|
else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
|
|
isp = ssp->smk_out->smk_known;
|
|
else
|
|
return -EOPNOTSUPP;
|
|
|
|
ilen = strlen(isp) + 1;
|
|
if (rc == 0) {
|
|
*buffer = isp;
|
|
rc = ilen;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
|
|
/**
|
|
* smack_inode_listsecurity - list the Smack attributes
|
|
* @inode: the object
|
|
* @buffer: where they go
|
|
* @buffer_size: size of buffer
|
|
*
|
|
* Returns 0 on success, -EINVAL otherwise
|
|
*/
|
|
static int smack_inode_listsecurity(struct inode *inode, char *buffer,
|
|
size_t buffer_size)
|
|
{
|
|
int len = strlen(XATTR_NAME_SMACK);
|
|
|
|
if (buffer != NULL && len <= buffer_size) {
|
|
memcpy(buffer, XATTR_NAME_SMACK, len);
|
|
return len;
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
|
|
/**
|
|
* smack_inode_getsecid - Extract inode's security id
|
|
* @inode: inode to extract the info from
|
|
* @secid: where result will be saved
|
|
*/
|
|
static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
|
|
{
|
|
struct inode_smack *isp = inode->i_security;
|
|
|
|
*secid = smack_to_secid(isp->smk_inode);
|
|
}
|
|
|
|
/*
|
|
* File Hooks
|
|
*/
|
|
|
|
/**
|
|
* smack_file_permission - Smack check on file operations
|
|
* @file: unused
|
|
* @mask: unused
|
|
*
|
|
* Returns 0
|
|
*
|
|
* Should access checks be done on each read or write?
|
|
* UNICOS and SELinux say yes.
|
|
* Trusted Solaris, Trusted Irix, and just about everyone else says no.
|
|
*
|
|
* I'll say no for now. Smack does not do the frequent
|
|
* label changing that SELinux does.
|
|
*/
|
|
static int smack_file_permission(struct file *file, int mask)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_file_alloc_security - assign a file security blob
|
|
* @file: the object
|
|
*
|
|
* The security blob for a file is a pointer to the master
|
|
* label list, so no allocation is done.
|
|
*
|
|
* Returns 0
|
|
*/
|
|
static int smack_file_alloc_security(struct file *file)
|
|
{
|
|
struct smack_known *skp = smk_of_current();
|
|
|
|
file->f_security = skp->smk_known;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_file_free_security - clear a file security blob
|
|
* @file: the object
|
|
*
|
|
* The security blob for a file is a pointer to the master
|
|
* label list, so no memory is freed.
|
|
*/
|
|
static void smack_file_free_security(struct file *file)
|
|
{
|
|
file->f_security = NULL;
|
|
}
|
|
|
|
/**
|
|
* smack_file_ioctl - Smack check on ioctls
|
|
* @file: the object
|
|
* @cmd: what to do
|
|
* @arg: unused
|
|
*
|
|
* Relies heavily on the correct use of the ioctl command conventions.
|
|
*
|
|
* Returns 0 if allowed, error code otherwise
|
|
*/
|
|
static int smack_file_ioctl(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
int rc = 0;
|
|
struct smk_audit_info ad;
|
|
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
|
|
smk_ad_setfield_u_fs_path(&ad, file->f_path);
|
|
|
|
if (_IOC_DIR(cmd) & _IOC_WRITE)
|
|
rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
|
|
|
|
if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
|
|
rc = smk_curacc(file->f_security, MAY_READ, &ad);
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_file_lock - Smack check on file locking
|
|
* @file: the object
|
|
* @cmd: unused
|
|
*
|
|
* Returns 0 if current has lock access, error code otherwise
|
|
*/
|
|
static int smack_file_lock(struct file *file, unsigned int cmd)
|
|
{
|
|
struct smk_audit_info ad;
|
|
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
|
|
smk_ad_setfield_u_fs_path(&ad, file->f_path);
|
|
return smk_curacc(file->f_security, MAY_LOCK, &ad);
|
|
}
|
|
|
|
/**
|
|
* smack_file_fcntl - Smack check on fcntl
|
|
* @file: the object
|
|
* @cmd: what action to check
|
|
* @arg: unused
|
|
*
|
|
* Generally these operations are harmless.
|
|
* File locking operations present an obvious mechanism
|
|
* for passing information, so they require write access.
|
|
*
|
|
* Returns 0 if current has access, error code otherwise
|
|
*/
|
|
static int smack_file_fcntl(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
struct smk_audit_info ad;
|
|
int rc = 0;
|
|
|
|
|
|
switch (cmd) {
|
|
case F_GETLK:
|
|
break;
|
|
case F_SETLK:
|
|
case F_SETLKW:
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
|
|
smk_ad_setfield_u_fs_path(&ad, file->f_path);
|
|
rc = smk_curacc(file->f_security, MAY_LOCK, &ad);
|
|
break;
|
|
case F_SETOWN:
|
|
case F_SETSIG:
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
|
|
smk_ad_setfield_u_fs_path(&ad, file->f_path);
|
|
rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_mmap_file :
|
|
* Check permissions for a mmap operation. The @file may be NULL, e.g.
|
|
* if mapping anonymous memory.
|
|
* @file contains the file structure for file to map (may be NULL).
|
|
* @reqprot contains the protection requested by the application.
|
|
* @prot contains the protection that will be applied by the kernel.
|
|
* @flags contains the operational flags.
|
|
* Return 0 if permission is granted.
|
|
*/
|
|
static int smack_mmap_file(struct file *file,
|
|
unsigned long reqprot, unsigned long prot,
|
|
unsigned long flags)
|
|
{
|
|
struct smack_known *skp;
|
|
struct smack_known *mkp;
|
|
struct smack_rule *srp;
|
|
struct task_smack *tsp;
|
|
char *osmack;
|
|
struct inode_smack *isp;
|
|
int may;
|
|
int mmay;
|
|
int tmay;
|
|
int rc;
|
|
|
|
if (file == NULL)
|
|
return 0;
|
|
|
|
isp = file_inode(file)->i_security;
|
|
if (isp->smk_mmap == NULL)
|
|
return 0;
|
|
mkp = isp->smk_mmap;
|
|
|
|
tsp = current_security();
|
|
skp = smk_of_current();
|
|
rc = 0;
|
|
|
|
rcu_read_lock();
|
|
/*
|
|
* For each Smack rule associated with the subject
|
|
* label verify that the SMACK64MMAP also has access
|
|
* to that rule's object label.
|
|
*/
|
|
list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
|
|
osmack = srp->smk_object;
|
|
/*
|
|
* Matching labels always allows access.
|
|
*/
|
|
if (mkp->smk_known == osmack)
|
|
continue;
|
|
/*
|
|
* If there is a matching local rule take
|
|
* that into account as well.
|
|
*/
|
|
may = smk_access_entry(srp->smk_subject->smk_known, osmack,
|
|
&tsp->smk_rules);
|
|
if (may == -ENOENT)
|
|
may = srp->smk_access;
|
|
else
|
|
may &= srp->smk_access;
|
|
/*
|
|
* If may is zero the SMACK64MMAP subject can't
|
|
* possibly have less access.
|
|
*/
|
|
if (may == 0)
|
|
continue;
|
|
|
|
/*
|
|
* Fetch the global list entry.
|
|
* If there isn't one a SMACK64MMAP subject
|
|
* can't have as much access as current.
|
|
*/
|
|
mmay = smk_access_entry(mkp->smk_known, osmack,
|
|
&mkp->smk_rules);
|
|
if (mmay == -ENOENT) {
|
|
rc = -EACCES;
|
|
break;
|
|
}
|
|
/*
|
|
* If there is a local entry it modifies the
|
|
* potential access, too.
|
|
*/
|
|
tmay = smk_access_entry(mkp->smk_known, osmack,
|
|
&tsp->smk_rules);
|
|
if (tmay != -ENOENT)
|
|
mmay &= tmay;
|
|
|
|
/*
|
|
* If there is any access available to current that is
|
|
* not available to a SMACK64MMAP subject
|
|
* deny access.
|
|
*/
|
|
if ((may | mmay) != mmay) {
|
|
rc = -EACCES;
|
|
break;
|
|
}
|
|
}
|
|
|
|
rcu_read_unlock();
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_file_set_fowner - set the file security blob value
|
|
* @file: object in question
|
|
*
|
|
* Returns 0
|
|
* Further research may be required on this one.
|
|
*/
|
|
static int smack_file_set_fowner(struct file *file)
|
|
{
|
|
struct smack_known *skp = smk_of_current();
|
|
|
|
file->f_security = skp->smk_known;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_file_send_sigiotask - Smack on sigio
|
|
* @tsk: The target task
|
|
* @fown: the object the signal come from
|
|
* @signum: unused
|
|
*
|
|
* Allow a privileged task to get signals even if it shouldn't
|
|
*
|
|
* Returns 0 if a subject with the object's smack could
|
|
* write to the task, an error code otherwise.
|
|
*/
|
|
static int smack_file_send_sigiotask(struct task_struct *tsk,
|
|
struct fown_struct *fown, int signum)
|
|
{
|
|
struct smack_known *skp;
|
|
struct smack_known *tkp = smk_of_task(tsk->cred->security);
|
|
struct file *file;
|
|
int rc;
|
|
struct smk_audit_info ad;
|
|
|
|
/*
|
|
* struct fown_struct is never outside the context of a struct file
|
|
*/
|
|
file = container_of(fown, struct file, f_owner);
|
|
|
|
/* we don't log here as rc can be overriden */
|
|
skp = smk_find_entry(file->f_security);
|
|
rc = smk_access(skp, tkp->smk_known, MAY_WRITE, NULL);
|
|
if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
|
|
rc = 0;
|
|
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
|
|
smk_ad_setfield_u_tsk(&ad, tsk);
|
|
smack_log(file->f_security, tkp->smk_known, MAY_WRITE, rc, &ad);
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_file_receive - Smack file receive check
|
|
* @file: the object
|
|
*
|
|
* Returns 0 if current has access, error code otherwise
|
|
*/
|
|
static int smack_file_receive(struct file *file)
|
|
{
|
|
int may = 0;
|
|
struct smk_audit_info ad;
|
|
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
|
|
smk_ad_setfield_u_fs_path(&ad, file->f_path);
|
|
/*
|
|
* This code relies on bitmasks.
|
|
*/
|
|
if (file->f_mode & FMODE_READ)
|
|
may = MAY_READ;
|
|
if (file->f_mode & FMODE_WRITE)
|
|
may |= MAY_WRITE;
|
|
|
|
return smk_curacc(file->f_security, may, &ad);
|
|
}
|
|
|
|
/**
|
|
* smack_file_open - Smack dentry open processing
|
|
* @file: the object
|
|
* @cred: task credential
|
|
*
|
|
* Set the security blob in the file structure.
|
|
* Allow the open only if the task has read access. There are
|
|
* many read operations (e.g. fstat) that you can do with an
|
|
* fd even if you have the file open write-only.
|
|
*
|
|
* Returns 0
|
|
*/
|
|
static int smack_file_open(struct file *file, const struct cred *cred)
|
|
{
|
|
struct task_smack *tsp = cred->security;
|
|
struct inode_smack *isp = file_inode(file)->i_security;
|
|
struct smk_audit_info ad;
|
|
int rc;
|
|
|
|
if (smack_privileged(CAP_MAC_OVERRIDE))
|
|
return 0;
|
|
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
|
|
smk_ad_setfield_u_fs_path(&ad, file->f_path);
|
|
rc = smk_access(tsp->smk_task, isp->smk_inode, MAY_READ, &ad);
|
|
if (rc == 0)
|
|
file->f_security = isp->smk_inode;
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* Task hooks
|
|
*/
|
|
|
|
/**
|
|
* smack_cred_alloc_blank - "allocate" blank task-level security credentials
|
|
* @new: the new credentials
|
|
* @gfp: the atomicity of any memory allocations
|
|
*
|
|
* Prepare a blank set of credentials for modification. This must allocate all
|
|
* the memory the LSM module might require such that cred_transfer() can
|
|
* complete without error.
|
|
*/
|
|
static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
|
|
{
|
|
struct task_smack *tsp;
|
|
|
|
tsp = new_task_smack(NULL, NULL, gfp);
|
|
if (tsp == NULL)
|
|
return -ENOMEM;
|
|
|
|
cred->security = tsp;
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/**
|
|
* smack_cred_free - "free" task-level security credentials
|
|
* @cred: the credentials in question
|
|
*
|
|
*/
|
|
static void smack_cred_free(struct cred *cred)
|
|
{
|
|
struct task_smack *tsp = cred->security;
|
|
struct smack_rule *rp;
|
|
struct list_head *l;
|
|
struct list_head *n;
|
|
|
|
if (tsp == NULL)
|
|
return;
|
|
cred->security = NULL;
|
|
|
|
list_for_each_safe(l, n, &tsp->smk_rules) {
|
|
rp = list_entry(l, struct smack_rule, list);
|
|
list_del(&rp->list);
|
|
kfree(rp);
|
|
}
|
|
kfree(tsp);
|
|
}
|
|
|
|
/**
|
|
* smack_cred_prepare - prepare new set of credentials for modification
|
|
* @new: the new credentials
|
|
* @old: the original credentials
|
|
* @gfp: the atomicity of any memory allocations
|
|
*
|
|
* Prepare a new set of credentials for modification.
|
|
*/
|
|
static int smack_cred_prepare(struct cred *new, const struct cred *old,
|
|
gfp_t gfp)
|
|
{
|
|
struct task_smack *old_tsp = old->security;
|
|
struct task_smack *new_tsp;
|
|
int rc;
|
|
|
|
new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp);
|
|
if (new_tsp == NULL)
|
|
return -ENOMEM;
|
|
|
|
rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
|
|
if (rc != 0)
|
|
return rc;
|
|
|
|
new->security = new_tsp;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_cred_transfer - Transfer the old credentials to the new credentials
|
|
* @new: the new credentials
|
|
* @old: the original credentials
|
|
*
|
|
* Fill in a set of blank credentials from another set of credentials.
|
|
*/
|
|
static void smack_cred_transfer(struct cred *new, const struct cred *old)
|
|
{
|
|
struct task_smack *old_tsp = old->security;
|
|
struct task_smack *new_tsp = new->security;
|
|
|
|
new_tsp->smk_task = old_tsp->smk_task;
|
|
new_tsp->smk_forked = old_tsp->smk_task;
|
|
mutex_init(&new_tsp->smk_rules_lock);
|
|
INIT_LIST_HEAD(&new_tsp->smk_rules);
|
|
|
|
|
|
/* cbs copy rule list */
|
|
}
|
|
|
|
/**
|
|
* smack_kernel_act_as - Set the subjective context in a set of credentials
|
|
* @new: points to the set of credentials to be modified.
|
|
* @secid: specifies the security ID to be set
|
|
*
|
|
* Set the security data for a kernel service.
|
|
*/
|
|
static int smack_kernel_act_as(struct cred *new, u32 secid)
|
|
{
|
|
struct task_smack *new_tsp = new->security;
|
|
struct smack_known *skp = smack_from_secid(secid);
|
|
|
|
if (skp == NULL)
|
|
return -EINVAL;
|
|
|
|
new_tsp->smk_task = skp;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_kernel_create_files_as - Set the file creation label in a set of creds
|
|
* @new: points to the set of credentials to be modified
|
|
* @inode: points to the inode to use as a reference
|
|
*
|
|
* Set the file creation context in a set of credentials to the same
|
|
* as the objective context of the specified inode
|
|
*/
|
|
static int smack_kernel_create_files_as(struct cred *new,
|
|
struct inode *inode)
|
|
{
|
|
struct inode_smack *isp = inode->i_security;
|
|
struct task_smack *tsp = new->security;
|
|
|
|
tsp->smk_forked = smk_find_entry(isp->smk_inode);
|
|
tsp->smk_task = tsp->smk_forked;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smk_curacc_on_task - helper to log task related access
|
|
* @p: the task object
|
|
* @access: the access requested
|
|
* @caller: name of the calling function for audit
|
|
*
|
|
* Return 0 if access is permitted
|
|
*/
|
|
static int smk_curacc_on_task(struct task_struct *p, int access,
|
|
const char *caller)
|
|
{
|
|
struct smk_audit_info ad;
|
|
struct smack_known *skp = smk_of_task(task_security(p));
|
|
|
|
smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
|
|
smk_ad_setfield_u_tsk(&ad, p);
|
|
return smk_curacc(skp->smk_known, access, &ad);
|
|
}
|
|
|
|
/**
|
|
* smack_task_setpgid - Smack check on setting pgid
|
|
* @p: the task object
|
|
* @pgid: unused
|
|
*
|
|
* Return 0 if write access is permitted
|
|
*/
|
|
static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
|
|
{
|
|
return smk_curacc_on_task(p, MAY_WRITE, __func__);
|
|
}
|
|
|
|
/**
|
|
* smack_task_getpgid - Smack access check for getpgid
|
|
* @p: the object task
|
|
*
|
|
* Returns 0 if current can read the object task, error code otherwise
|
|
*/
|
|
static int smack_task_getpgid(struct task_struct *p)
|
|
{
|
|
return smk_curacc_on_task(p, MAY_READ, __func__);
|
|
}
|
|
|
|
/**
|
|
* smack_task_getsid - Smack access check for getsid
|
|
* @p: the object task
|
|
*
|
|
* Returns 0 if current can read the object task, error code otherwise
|
|
*/
|
|
static int smack_task_getsid(struct task_struct *p)
|
|
{
|
|
return smk_curacc_on_task(p, MAY_READ, __func__);
|
|
}
|
|
|
|
/**
|
|
* smack_task_getsecid - get the secid of the task
|
|
* @p: the object task
|
|
* @secid: where to put the result
|
|
*
|
|
* Sets the secid to contain a u32 version of the smack label.
|
|
*/
|
|
static void smack_task_getsecid(struct task_struct *p, u32 *secid)
|
|
{
|
|
struct smack_known *skp = smk_of_task(task_security(p));
|
|
|
|
*secid = skp->smk_secid;
|
|
}
|
|
|
|
/**
|
|
* smack_task_setnice - Smack check on setting nice
|
|
* @p: the task object
|
|
* @nice: unused
|
|
*
|
|
* Return 0 if write access is permitted
|
|
*/
|
|
static int smack_task_setnice(struct task_struct *p, int nice)
|
|
{
|
|
int rc;
|
|
|
|
rc = cap_task_setnice(p, nice);
|
|
if (rc == 0)
|
|
rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_task_setioprio - Smack check on setting ioprio
|
|
* @p: the task object
|
|
* @ioprio: unused
|
|
*
|
|
* Return 0 if write access is permitted
|
|
*/
|
|
static int smack_task_setioprio(struct task_struct *p, int ioprio)
|
|
{
|
|
int rc;
|
|
|
|
rc = cap_task_setioprio(p, ioprio);
|
|
if (rc == 0)
|
|
rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_task_getioprio - Smack check on reading ioprio
|
|
* @p: the task object
|
|
*
|
|
* Return 0 if read access is permitted
|
|
*/
|
|
static int smack_task_getioprio(struct task_struct *p)
|
|
{
|
|
return smk_curacc_on_task(p, MAY_READ, __func__);
|
|
}
|
|
|
|
/**
|
|
* smack_task_setscheduler - Smack check on setting scheduler
|
|
* @p: the task object
|
|
* @policy: unused
|
|
* @lp: unused
|
|
*
|
|
* Return 0 if read access is permitted
|
|
*/
|
|
static int smack_task_setscheduler(struct task_struct *p)
|
|
{
|
|
int rc;
|
|
|
|
rc = cap_task_setscheduler(p);
|
|
if (rc == 0)
|
|
rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_task_getscheduler - Smack check on reading scheduler
|
|
* @p: the task object
|
|
*
|
|
* Return 0 if read access is permitted
|
|
*/
|
|
static int smack_task_getscheduler(struct task_struct *p)
|
|
{
|
|
return smk_curacc_on_task(p, MAY_READ, __func__);
|
|
}
|
|
|
|
/**
|
|
* smack_task_movememory - Smack check on moving memory
|
|
* @p: the task object
|
|
*
|
|
* Return 0 if write access is permitted
|
|
*/
|
|
static int smack_task_movememory(struct task_struct *p)
|
|
{
|
|
return smk_curacc_on_task(p, MAY_WRITE, __func__);
|
|
}
|
|
|
|
/**
|
|
* smack_task_kill - Smack check on signal delivery
|
|
* @p: the task object
|
|
* @info: unused
|
|
* @sig: unused
|
|
* @secid: identifies the smack to use in lieu of current's
|
|
*
|
|
* Return 0 if write access is permitted
|
|
*
|
|
* The secid behavior is an artifact of an SELinux hack
|
|
* in the USB code. Someday it may go away.
|
|
*/
|
|
static int smack_task_kill(struct task_struct *p, struct siginfo *info,
|
|
int sig, u32 secid)
|
|
{
|
|
struct smk_audit_info ad;
|
|
struct smack_known *skp;
|
|
struct smack_known *tkp = smk_of_task(task_security(p));
|
|
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
|
|
smk_ad_setfield_u_tsk(&ad, p);
|
|
/*
|
|
* Sending a signal requires that the sender
|
|
* can write the receiver.
|
|
*/
|
|
if (secid == 0)
|
|
return smk_curacc(tkp->smk_known, MAY_WRITE, &ad);
|
|
/*
|
|
* If the secid isn't 0 we're dealing with some USB IO
|
|
* specific behavior. This is not clean. For one thing
|
|
* we can't take privilege into account.
|
|
*/
|
|
skp = smack_from_secid(secid);
|
|
return smk_access(skp, tkp->smk_known, MAY_WRITE, &ad);
|
|
}
|
|
|
|
/**
|
|
* smack_task_wait - Smack access check for waiting
|
|
* @p: task to wait for
|
|
*
|
|
* Returns 0
|
|
*/
|
|
static int smack_task_wait(struct task_struct *p)
|
|
{
|
|
/*
|
|
* Allow the operation to succeed.
|
|
* Zombies are bad.
|
|
* In userless environments (e.g. phones) programs
|
|
* get marked with SMACK64EXEC and even if the parent
|
|
* and child shouldn't be talking the parent still
|
|
* may expect to know when the child exits.
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_task_to_inode - copy task smack into the inode blob
|
|
* @p: task to copy from
|
|
* @inode: inode to copy to
|
|
*
|
|
* Sets the smack pointer in the inode security blob
|
|
*/
|
|
static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
|
|
{
|
|
struct inode_smack *isp = inode->i_security;
|
|
struct smack_known *skp = smk_of_task(task_security(p));
|
|
|
|
isp->smk_inode = skp->smk_known;
|
|
}
|
|
|
|
/*
|
|
* Socket hooks.
|
|
*/
|
|
|
|
/**
|
|
* smack_sk_alloc_security - Allocate a socket blob
|
|
* @sk: the socket
|
|
* @family: unused
|
|
* @gfp_flags: memory allocation flags
|
|
*
|
|
* Assign Smack pointers to current
|
|
*
|
|
* Returns 0 on success, -ENOMEM is there's no memory
|
|
*/
|
|
static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
|
|
{
|
|
struct smack_known *skp = smk_of_current();
|
|
struct socket_smack *ssp;
|
|
|
|
ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
|
|
if (ssp == NULL)
|
|
return -ENOMEM;
|
|
|
|
ssp->smk_in = skp;
|
|
ssp->smk_out = skp;
|
|
ssp->smk_packet = NULL;
|
|
|
|
sk->sk_security = ssp;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_sk_free_security - Free a socket blob
|
|
* @sk: the socket
|
|
*
|
|
* Clears the blob pointer
|
|
*/
|
|
static void smack_sk_free_security(struct sock *sk)
|
|
{
|
|
kfree(sk->sk_security);
|
|
}
|
|
|
|
/**
|
|
* smack_host_label - check host based restrictions
|
|
* @sip: the object end
|
|
*
|
|
* looks for host based access restrictions
|
|
*
|
|
* This version will only be appropriate for really small sets of single label
|
|
* hosts. The caller is responsible for ensuring that the RCU read lock is
|
|
* taken before calling this function.
|
|
*
|
|
* Returns the label of the far end or NULL if it's not special.
|
|
*/
|
|
static char *smack_host_label(struct sockaddr_in *sip)
|
|
{
|
|
struct smk_netlbladdr *snp;
|
|
struct in_addr *siap = &sip->sin_addr;
|
|
|
|
if (siap->s_addr == 0)
|
|
return NULL;
|
|
|
|
list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list)
|
|
/*
|
|
* we break after finding the first match because
|
|
* the list is sorted from longest to shortest mask
|
|
* so we have found the most specific match
|
|
*/
|
|
if ((&snp->smk_host.sin_addr)->s_addr ==
|
|
(siap->s_addr & (&snp->smk_mask)->s_addr)) {
|
|
/* we have found the special CIPSO option */
|
|
if (snp->smk_label == smack_cipso_option)
|
|
return NULL;
|
|
return snp->smk_label;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* smack_netlabel - Set the secattr on a socket
|
|
* @sk: the socket
|
|
* @labeled: socket label scheme
|
|
*
|
|
* Convert the outbound smack value (smk_out) to a
|
|
* secattr and attach it to the socket.
|
|
*
|
|
* Returns 0 on success or an error code
|
|
*/
|
|
static int smack_netlabel(struct sock *sk, int labeled)
|
|
{
|
|
struct smack_known *skp;
|
|
struct socket_smack *ssp = sk->sk_security;
|
|
int rc = 0;
|
|
|
|
/*
|
|
* Usually the netlabel code will handle changing the
|
|
* packet labeling based on the label.
|
|
* The case of a single label host is different, because
|
|
* a single label host should never get a labeled packet
|
|
* even though the label is usually associated with a packet
|
|
* label.
|
|
*/
|
|
local_bh_disable();
|
|
bh_lock_sock_nested(sk);
|
|
|
|
if (ssp->smk_out == smack_net_ambient ||
|
|
labeled == SMACK_UNLABELED_SOCKET)
|
|
netlbl_sock_delattr(sk);
|
|
else {
|
|
skp = ssp->smk_out;
|
|
rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
|
|
}
|
|
|
|
bh_unlock_sock(sk);
|
|
local_bh_enable();
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_netlbel_send - Set the secattr on a socket and perform access checks
|
|
* @sk: the socket
|
|
* @sap: the destination address
|
|
*
|
|
* Set the correct secattr for the given socket based on the destination
|
|
* address and perform any outbound access checks needed.
|
|
*
|
|
* Returns 0 on success or an error code.
|
|
*
|
|
*/
|
|
static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
|
|
{
|
|
struct smack_known *skp;
|
|
int rc;
|
|
int sk_lbl;
|
|
char *hostsp;
|
|
struct socket_smack *ssp = sk->sk_security;
|
|
struct smk_audit_info ad;
|
|
|
|
rcu_read_lock();
|
|
hostsp = smack_host_label(sap);
|
|
if (hostsp != NULL) {
|
|
#ifdef CONFIG_AUDIT
|
|
struct lsm_network_audit net;
|
|
|
|
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
|
|
ad.a.u.net->family = sap->sin_family;
|
|
ad.a.u.net->dport = sap->sin_port;
|
|
ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
|
|
#endif
|
|
sk_lbl = SMACK_UNLABELED_SOCKET;
|
|
skp = ssp->smk_out;
|
|
rc = smk_access(skp, hostsp, MAY_WRITE, &ad);
|
|
} else {
|
|
sk_lbl = SMACK_CIPSO_SOCKET;
|
|
rc = 0;
|
|
}
|
|
rcu_read_unlock();
|
|
if (rc != 0)
|
|
return rc;
|
|
|
|
return smack_netlabel(sk, sk_lbl);
|
|
}
|
|
|
|
/**
|
|
* smk_ipv6_port_label - Smack port access table management
|
|
* @sock: socket
|
|
* @address: address
|
|
*
|
|
* Create or update the port list entry
|
|
*/
|
|
static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct sockaddr_in6 *addr6;
|
|
struct socket_smack *ssp = sock->sk->sk_security;
|
|
struct smk_port_label *spp;
|
|
unsigned short port = 0;
|
|
|
|
if (address == NULL) {
|
|
/*
|
|
* This operation is changing the Smack information
|
|
* on the bound socket. Take the changes to the port
|
|
* as well.
|
|
*/
|
|
list_for_each_entry(spp, &smk_ipv6_port_list, list) {
|
|
if (sk != spp->smk_sock)
|
|
continue;
|
|
spp->smk_in = ssp->smk_in;
|
|
spp->smk_out = ssp->smk_out;
|
|
return;
|
|
}
|
|
/*
|
|
* A NULL address is only used for updating existing
|
|
* bound entries. If there isn't one, it's OK.
|
|
*/
|
|
return;
|
|
}
|
|
|
|
addr6 = (struct sockaddr_in6 *)address;
|
|
port = ntohs(addr6->sin6_port);
|
|
/*
|
|
* This is a special case that is safely ignored.
|
|
*/
|
|
if (port == 0)
|
|
return;
|
|
|
|
/*
|
|
* Look for an existing port list entry.
|
|
* This is an indication that a port is getting reused.
|
|
*/
|
|
list_for_each_entry(spp, &smk_ipv6_port_list, list) {
|
|
if (spp->smk_port != port)
|
|
continue;
|
|
spp->smk_port = port;
|
|
spp->smk_sock = sk;
|
|
spp->smk_in = ssp->smk_in;
|
|
spp->smk_out = ssp->smk_out;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* A new port entry is required.
|
|
*/
|
|
spp = kzalloc(sizeof(*spp), GFP_KERNEL);
|
|
if (spp == NULL)
|
|
return;
|
|
|
|
spp->smk_port = port;
|
|
spp->smk_sock = sk;
|
|
spp->smk_in = ssp->smk_in;
|
|
spp->smk_out = ssp->smk_out;
|
|
|
|
list_add(&spp->list, &smk_ipv6_port_list);
|
|
return;
|
|
}
|
|
|
|
/**
|
|
* smk_ipv6_port_check - check Smack port access
|
|
* @sock: socket
|
|
* @address: address
|
|
*
|
|
* Create or update the port list entry
|
|
*/
|
|
static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
|
|
int act)
|
|
{
|
|
__be16 *bep;
|
|
__be32 *be32p;
|
|
struct smk_port_label *spp;
|
|
struct socket_smack *ssp = sk->sk_security;
|
|
struct smack_known *skp;
|
|
unsigned short port = 0;
|
|
char *object;
|
|
struct smk_audit_info ad;
|
|
#ifdef CONFIG_AUDIT
|
|
struct lsm_network_audit net;
|
|
#endif
|
|
|
|
if (act == SMK_RECEIVING) {
|
|
skp = smack_net_ambient;
|
|
object = ssp->smk_in->smk_known;
|
|
} else {
|
|
skp = ssp->smk_out;
|
|
object = smack_net_ambient->smk_known;
|
|
}
|
|
|
|
/*
|
|
* Get the IP address and port from the address.
|
|
*/
|
|
port = ntohs(address->sin6_port);
|
|
bep = (__be16 *)(&address->sin6_addr);
|
|
be32p = (__be32 *)(&address->sin6_addr);
|
|
|
|
/*
|
|
* It's remote, so port lookup does no good.
|
|
*/
|
|
if (be32p[0] || be32p[1] || be32p[2] || bep[6] || ntohs(bep[7]) != 1)
|
|
goto auditout;
|
|
|
|
/*
|
|
* It's local so the send check has to have passed.
|
|
*/
|
|
if (act == SMK_RECEIVING) {
|
|
skp = &smack_known_web;
|
|
goto auditout;
|
|
}
|
|
|
|
list_for_each_entry(spp, &smk_ipv6_port_list, list) {
|
|
if (spp->smk_port != port)
|
|
continue;
|
|
object = spp->smk_in->smk_known;
|
|
if (act == SMK_CONNECTING)
|
|
ssp->smk_packet = spp->smk_out;
|
|
break;
|
|
}
|
|
|
|
auditout:
|
|
|
|
#ifdef CONFIG_AUDIT
|
|
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
|
|
ad.a.u.net->family = sk->sk_family;
|
|
ad.a.u.net->dport = port;
|
|
if (act == SMK_RECEIVING)
|
|
ad.a.u.net->v6info.saddr = address->sin6_addr;
|
|
else
|
|
ad.a.u.net->v6info.daddr = address->sin6_addr;
|
|
#endif
|
|
return smk_access(skp, object, MAY_WRITE, &ad);
|
|
}
|
|
|
|
/**
|
|
* smack_inode_setsecurity - set smack xattrs
|
|
* @inode: the object
|
|
* @name: attribute name
|
|
* @value: attribute value
|
|
* @size: size of the attribute
|
|
* @flags: unused
|
|
*
|
|
* Sets the named attribute in the appropriate blob
|
|
*
|
|
* Returns 0 on success, or an error code
|
|
*/
|
|
static int smack_inode_setsecurity(struct inode *inode, const char *name,
|
|
const void *value, size_t size, int flags)
|
|
{
|
|
struct smack_known *skp;
|
|
struct inode_smack *nsp = inode->i_security;
|
|
struct socket_smack *ssp;
|
|
struct socket *sock;
|
|
int rc = 0;
|
|
|
|
if (value == NULL || size > SMK_LONGLABEL || size == 0)
|
|
return -EINVAL;
|
|
|
|
skp = smk_import_entry(value, size);
|
|
if (skp == NULL)
|
|
return -EINVAL;
|
|
|
|
if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
|
|
nsp->smk_inode = skp->smk_known;
|
|
nsp->smk_flags |= SMK_INODE_INSTANT;
|
|
return 0;
|
|
}
|
|
/*
|
|
* The rest of the Smack xattrs are only on sockets.
|
|
*/
|
|
if (inode->i_sb->s_magic != SOCKFS_MAGIC)
|
|
return -EOPNOTSUPP;
|
|
|
|
sock = SOCKET_I(inode);
|
|
if (sock == NULL || sock->sk == NULL)
|
|
return -EOPNOTSUPP;
|
|
|
|
ssp = sock->sk->sk_security;
|
|
|
|
if (strcmp(name, XATTR_SMACK_IPIN) == 0)
|
|
ssp->smk_in = skp;
|
|
else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
|
|
ssp->smk_out = skp;
|
|
if (sock->sk->sk_family == PF_INET) {
|
|
rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
|
|
if (rc != 0)
|
|
printk(KERN_WARNING
|
|
"Smack: \"%s\" netlbl error %d.\n",
|
|
__func__, -rc);
|
|
}
|
|
} else
|
|
return -EOPNOTSUPP;
|
|
|
|
if (sock->sk->sk_family == PF_INET6)
|
|
smk_ipv6_port_label(sock, NULL);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_socket_post_create - finish socket setup
|
|
* @sock: the socket
|
|
* @family: protocol family
|
|
* @type: unused
|
|
* @protocol: unused
|
|
* @kern: unused
|
|
*
|
|
* Sets the netlabel information on the socket
|
|
*
|
|
* Returns 0 on success, and error code otherwise
|
|
*/
|
|
static int smack_socket_post_create(struct socket *sock, int family,
|
|
int type, int protocol, int kern)
|
|
{
|
|
if (family != PF_INET || sock->sk == NULL)
|
|
return 0;
|
|
/*
|
|
* Set the outbound netlbl.
|
|
*/
|
|
return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
|
|
}
|
|
|
|
/**
|
|
* smack_socket_bind - record port binding information.
|
|
* @sock: the socket
|
|
* @address: the port address
|
|
* @addrlen: size of the address
|
|
*
|
|
* Records the label bound to a port.
|
|
*
|
|
* Returns 0
|
|
*/
|
|
static int smack_socket_bind(struct socket *sock, struct sockaddr *address,
|
|
int addrlen)
|
|
{
|
|
if (sock->sk != NULL && sock->sk->sk_family == PF_INET6)
|
|
smk_ipv6_port_label(sock, address);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_socket_connect - connect access check
|
|
* @sock: the socket
|
|
* @sap: the other end
|
|
* @addrlen: size of sap
|
|
*
|
|
* Verifies that a connection may be possible
|
|
*
|
|
* Returns 0 on success, and error code otherwise
|
|
*/
|
|
static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
|
|
int addrlen)
|
|
{
|
|
int rc = 0;
|
|
|
|
if (sock->sk == NULL)
|
|
return 0;
|
|
|
|
switch (sock->sk->sk_family) {
|
|
case PF_INET:
|
|
if (addrlen < sizeof(struct sockaddr_in))
|
|
return -EINVAL;
|
|
rc = smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
|
|
break;
|
|
case PF_INET6:
|
|
if (addrlen < sizeof(struct sockaddr_in6))
|
|
return -EINVAL;
|
|
rc = smk_ipv6_port_check(sock->sk, (struct sockaddr_in6 *)sap,
|
|
SMK_CONNECTING);
|
|
break;
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_flags_to_may - convert S_ to MAY_ values
|
|
* @flags: the S_ value
|
|
*
|
|
* Returns the equivalent MAY_ value
|
|
*/
|
|
static int smack_flags_to_may(int flags)
|
|
{
|
|
int may = 0;
|
|
|
|
if (flags & S_IRUGO)
|
|
may |= MAY_READ;
|
|
if (flags & S_IWUGO)
|
|
may |= MAY_WRITE;
|
|
if (flags & S_IXUGO)
|
|
may |= MAY_EXEC;
|
|
|
|
return may;
|
|
}
|
|
|
|
/**
|
|
* smack_msg_msg_alloc_security - Set the security blob for msg_msg
|
|
* @msg: the object
|
|
*
|
|
* Returns 0
|
|
*/
|
|
static int smack_msg_msg_alloc_security(struct msg_msg *msg)
|
|
{
|
|
struct smack_known *skp = smk_of_current();
|
|
|
|
msg->security = skp->smk_known;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_msg_msg_free_security - Clear the security blob for msg_msg
|
|
* @msg: the object
|
|
*
|
|
* Clears the blob pointer
|
|
*/
|
|
static void smack_msg_msg_free_security(struct msg_msg *msg)
|
|
{
|
|
msg->security = NULL;
|
|
}
|
|
|
|
/**
|
|
* smack_of_shm - the smack pointer for the shm
|
|
* @shp: the object
|
|
*
|
|
* Returns a pointer to the smack value
|
|
*/
|
|
static char *smack_of_shm(struct shmid_kernel *shp)
|
|
{
|
|
return (char *)shp->shm_perm.security;
|
|
}
|
|
|
|
/**
|
|
* smack_shm_alloc_security - Set the security blob for shm
|
|
* @shp: the object
|
|
*
|
|
* Returns 0
|
|
*/
|
|
static int smack_shm_alloc_security(struct shmid_kernel *shp)
|
|
{
|
|
struct kern_ipc_perm *isp = &shp->shm_perm;
|
|
struct smack_known *skp = smk_of_current();
|
|
|
|
isp->security = skp->smk_known;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_shm_free_security - Clear the security blob for shm
|
|
* @shp: the object
|
|
*
|
|
* Clears the blob pointer
|
|
*/
|
|
static void smack_shm_free_security(struct shmid_kernel *shp)
|
|
{
|
|
struct kern_ipc_perm *isp = &shp->shm_perm;
|
|
|
|
isp->security = NULL;
|
|
}
|
|
|
|
/**
|
|
* smk_curacc_shm : check if current has access on shm
|
|
* @shp : the object
|
|
* @access : access requested
|
|
*
|
|
* Returns 0 if current has the requested access, error code otherwise
|
|
*/
|
|
static int smk_curacc_shm(struct shmid_kernel *shp, int access)
|
|
{
|
|
char *ssp = smack_of_shm(shp);
|
|
struct smk_audit_info ad;
|
|
|
|
#ifdef CONFIG_AUDIT
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
|
|
ad.a.u.ipc_id = shp->shm_perm.id;
|
|
#endif
|
|
return smk_curacc(ssp, access, &ad);
|
|
}
|
|
|
|
/**
|
|
* smack_shm_associate - Smack access check for shm
|
|
* @shp: the object
|
|
* @shmflg: access requested
|
|
*
|
|
* Returns 0 if current has the requested access, error code otherwise
|
|
*/
|
|
static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
|
|
{
|
|
int may;
|
|
|
|
may = smack_flags_to_may(shmflg);
|
|
return smk_curacc_shm(shp, may);
|
|
}
|
|
|
|
/**
|
|
* smack_shm_shmctl - Smack access check for shm
|
|
* @shp: the object
|
|
* @cmd: what it wants to do
|
|
*
|
|
* Returns 0 if current has the requested access, error code otherwise
|
|
*/
|
|
static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
|
|
{
|
|
int may;
|
|
|
|
switch (cmd) {
|
|
case IPC_STAT:
|
|
case SHM_STAT:
|
|
may = MAY_READ;
|
|
break;
|
|
case IPC_SET:
|
|
case SHM_LOCK:
|
|
case SHM_UNLOCK:
|
|
case IPC_RMID:
|
|
may = MAY_READWRITE;
|
|
break;
|
|
case IPC_INFO:
|
|
case SHM_INFO:
|
|
/*
|
|
* System level information.
|
|
*/
|
|
return 0;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
return smk_curacc_shm(shp, may);
|
|
}
|
|
|
|
/**
|
|
* smack_shm_shmat - Smack access for shmat
|
|
* @shp: the object
|
|
* @shmaddr: unused
|
|
* @shmflg: access requested
|
|
*
|
|
* Returns 0 if current has the requested access, error code otherwise
|
|
*/
|
|
static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
|
|
int shmflg)
|
|
{
|
|
int may;
|
|
|
|
may = smack_flags_to_may(shmflg);
|
|
return smk_curacc_shm(shp, may);
|
|
}
|
|
|
|
/**
|
|
* smack_of_sem - the smack pointer for the sem
|
|
* @sma: the object
|
|
*
|
|
* Returns a pointer to the smack value
|
|
*/
|
|
static char *smack_of_sem(struct sem_array *sma)
|
|
{
|
|
return (char *)sma->sem_perm.security;
|
|
}
|
|
|
|
/**
|
|
* smack_sem_alloc_security - Set the security blob for sem
|
|
* @sma: the object
|
|
*
|
|
* Returns 0
|
|
*/
|
|
static int smack_sem_alloc_security(struct sem_array *sma)
|
|
{
|
|
struct kern_ipc_perm *isp = &sma->sem_perm;
|
|
struct smack_known *skp = smk_of_current();
|
|
|
|
isp->security = skp->smk_known;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_sem_free_security - Clear the security blob for sem
|
|
* @sma: the object
|
|
*
|
|
* Clears the blob pointer
|
|
*/
|
|
static void smack_sem_free_security(struct sem_array *sma)
|
|
{
|
|
struct kern_ipc_perm *isp = &sma->sem_perm;
|
|
|
|
isp->security = NULL;
|
|
}
|
|
|
|
/**
|
|
* smk_curacc_sem : check if current has access on sem
|
|
* @sma : the object
|
|
* @access : access requested
|
|
*
|
|
* Returns 0 if current has the requested access, error code otherwise
|
|
*/
|
|
static int smk_curacc_sem(struct sem_array *sma, int access)
|
|
{
|
|
char *ssp = smack_of_sem(sma);
|
|
struct smk_audit_info ad;
|
|
|
|
#ifdef CONFIG_AUDIT
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
|
|
ad.a.u.ipc_id = sma->sem_perm.id;
|
|
#endif
|
|
return smk_curacc(ssp, access, &ad);
|
|
}
|
|
|
|
/**
|
|
* smack_sem_associate - Smack access check for sem
|
|
* @sma: the object
|
|
* @semflg: access requested
|
|
*
|
|
* Returns 0 if current has the requested access, error code otherwise
|
|
*/
|
|
static int smack_sem_associate(struct sem_array *sma, int semflg)
|
|
{
|
|
int may;
|
|
|
|
may = smack_flags_to_may(semflg);
|
|
return smk_curacc_sem(sma, may);
|
|
}
|
|
|
|
/**
|
|
* smack_sem_shmctl - Smack access check for sem
|
|
* @sma: the object
|
|
* @cmd: what it wants to do
|
|
*
|
|
* Returns 0 if current has the requested access, error code otherwise
|
|
*/
|
|
static int smack_sem_semctl(struct sem_array *sma, int cmd)
|
|
{
|
|
int may;
|
|
|
|
switch (cmd) {
|
|
case GETPID:
|
|
case GETNCNT:
|
|
case GETZCNT:
|
|
case GETVAL:
|
|
case GETALL:
|
|
case IPC_STAT:
|
|
case SEM_STAT:
|
|
may = MAY_READ;
|
|
break;
|
|
case SETVAL:
|
|
case SETALL:
|
|
case IPC_RMID:
|
|
case IPC_SET:
|
|
may = MAY_READWRITE;
|
|
break;
|
|
case IPC_INFO:
|
|
case SEM_INFO:
|
|
/*
|
|
* System level information
|
|
*/
|
|
return 0;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
return smk_curacc_sem(sma, may);
|
|
}
|
|
|
|
/**
|
|
* smack_sem_semop - Smack checks of semaphore operations
|
|
* @sma: the object
|
|
* @sops: unused
|
|
* @nsops: unused
|
|
* @alter: unused
|
|
*
|
|
* Treated as read and write in all cases.
|
|
*
|
|
* Returns 0 if access is allowed, error code otherwise
|
|
*/
|
|
static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
|
|
unsigned nsops, int alter)
|
|
{
|
|
return smk_curacc_sem(sma, MAY_READWRITE);
|
|
}
|
|
|
|
/**
|
|
* smack_msg_alloc_security - Set the security blob for msg
|
|
* @msq: the object
|
|
*
|
|
* Returns 0
|
|
*/
|
|
static int smack_msg_queue_alloc_security(struct msg_queue *msq)
|
|
{
|
|
struct kern_ipc_perm *kisp = &msq->q_perm;
|
|
struct smack_known *skp = smk_of_current();
|
|
|
|
kisp->security = skp->smk_known;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_msg_free_security - Clear the security blob for msg
|
|
* @msq: the object
|
|
*
|
|
* Clears the blob pointer
|
|
*/
|
|
static void smack_msg_queue_free_security(struct msg_queue *msq)
|
|
{
|
|
struct kern_ipc_perm *kisp = &msq->q_perm;
|
|
|
|
kisp->security = NULL;
|
|
}
|
|
|
|
/**
|
|
* smack_of_msq - the smack pointer for the msq
|
|
* @msq: the object
|
|
*
|
|
* Returns a pointer to the smack value
|
|
*/
|
|
static char *smack_of_msq(struct msg_queue *msq)
|
|
{
|
|
return (char *)msq->q_perm.security;
|
|
}
|
|
|
|
/**
|
|
* smk_curacc_msq : helper to check if current has access on msq
|
|
* @msq : the msq
|
|
* @access : access requested
|
|
*
|
|
* return 0 if current has access, error otherwise
|
|
*/
|
|
static int smk_curacc_msq(struct msg_queue *msq, int access)
|
|
{
|
|
char *msp = smack_of_msq(msq);
|
|
struct smk_audit_info ad;
|
|
|
|
#ifdef CONFIG_AUDIT
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
|
|
ad.a.u.ipc_id = msq->q_perm.id;
|
|
#endif
|
|
return smk_curacc(msp, access, &ad);
|
|
}
|
|
|
|
/**
|
|
* smack_msg_queue_associate - Smack access check for msg_queue
|
|
* @msq: the object
|
|
* @msqflg: access requested
|
|
*
|
|
* Returns 0 if current has the requested access, error code otherwise
|
|
*/
|
|
static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
|
|
{
|
|
int may;
|
|
|
|
may = smack_flags_to_may(msqflg);
|
|
return smk_curacc_msq(msq, may);
|
|
}
|
|
|
|
/**
|
|
* smack_msg_queue_msgctl - Smack access check for msg_queue
|
|
* @msq: the object
|
|
* @cmd: what it wants to do
|
|
*
|
|
* Returns 0 if current has the requested access, error code otherwise
|
|
*/
|
|
static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
|
|
{
|
|
int may;
|
|
|
|
switch (cmd) {
|
|
case IPC_STAT:
|
|
case MSG_STAT:
|
|
may = MAY_READ;
|
|
break;
|
|
case IPC_SET:
|
|
case IPC_RMID:
|
|
may = MAY_READWRITE;
|
|
break;
|
|
case IPC_INFO:
|
|
case MSG_INFO:
|
|
/*
|
|
* System level information
|
|
*/
|
|
return 0;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
return smk_curacc_msq(msq, may);
|
|
}
|
|
|
|
/**
|
|
* smack_msg_queue_msgsnd - Smack access check for msg_queue
|
|
* @msq: the object
|
|
* @msg: unused
|
|
* @msqflg: access requested
|
|
*
|
|
* Returns 0 if current has the requested access, error code otherwise
|
|
*/
|
|
static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
|
|
int msqflg)
|
|
{
|
|
int may;
|
|
|
|
may = smack_flags_to_may(msqflg);
|
|
return smk_curacc_msq(msq, may);
|
|
}
|
|
|
|
/**
|
|
* smack_msg_queue_msgsnd - Smack access check for msg_queue
|
|
* @msq: the object
|
|
* @msg: unused
|
|
* @target: unused
|
|
* @type: unused
|
|
* @mode: unused
|
|
*
|
|
* Returns 0 if current has read and write access, error code otherwise
|
|
*/
|
|
static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
|
|
struct task_struct *target, long type, int mode)
|
|
{
|
|
return smk_curacc_msq(msq, MAY_READWRITE);
|
|
}
|
|
|
|
/**
|
|
* smack_ipc_permission - Smack access for ipc_permission()
|
|
* @ipp: the object permissions
|
|
* @flag: access requested
|
|
*
|
|
* Returns 0 if current has read and write access, error code otherwise
|
|
*/
|
|
static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
|
|
{
|
|
char *isp = ipp->security;
|
|
int may = smack_flags_to_may(flag);
|
|
struct smk_audit_info ad;
|
|
|
|
#ifdef CONFIG_AUDIT
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
|
|
ad.a.u.ipc_id = ipp->id;
|
|
#endif
|
|
return smk_curacc(isp, may, &ad);
|
|
}
|
|
|
|
/**
|
|
* smack_ipc_getsecid - Extract smack security id
|
|
* @ipp: the object permissions
|
|
* @secid: where result will be saved
|
|
*/
|
|
static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
|
|
{
|
|
char *smack = ipp->security;
|
|
|
|
*secid = smack_to_secid(smack);
|
|
}
|
|
|
|
/**
|
|
* smack_d_instantiate - Make sure the blob is correct on an inode
|
|
* @opt_dentry: dentry where inode will be attached
|
|
* @inode: the object
|
|
*
|
|
* Set the inode's security blob if it hasn't been done already.
|
|
*/
|
|
static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
|
|
{
|
|
struct super_block *sbp;
|
|
struct superblock_smack *sbsp;
|
|
struct inode_smack *isp;
|
|
struct smack_known *skp;
|
|
struct smack_known *ckp = smk_of_current();
|
|
char *final;
|
|
char trattr[TRANS_TRUE_SIZE];
|
|
int transflag = 0;
|
|
int rc;
|
|
struct dentry *dp;
|
|
|
|
if (inode == NULL)
|
|
return;
|
|
|
|
isp = inode->i_security;
|
|
|
|
mutex_lock(&isp->smk_lock);
|
|
/*
|
|
* If the inode is already instantiated
|
|
* take the quick way out
|
|
*/
|
|
if (isp->smk_flags & SMK_INODE_INSTANT)
|
|
goto unlockandout;
|
|
|
|
sbp = inode->i_sb;
|
|
sbsp = sbp->s_security;
|
|
/*
|
|
* We're going to use the superblock default label
|
|
* if there's no label on the file.
|
|
*/
|
|
final = sbsp->smk_default;
|
|
|
|
/*
|
|
* If this is the root inode the superblock
|
|
* may be in the process of initialization.
|
|
* If that is the case use the root value out
|
|
* of the superblock.
|
|
*/
|
|
if (opt_dentry->d_parent == opt_dentry) {
|
|
if (sbp->s_magic == CGROUP_SUPER_MAGIC) {
|
|
/*
|
|
* The cgroup filesystem is never mounted,
|
|
* so there's no opportunity to set the mount
|
|
* options.
|
|
*/
|
|
sbsp->smk_root = smack_known_star.smk_known;
|
|
sbsp->smk_default = smack_known_star.smk_known;
|
|
}
|
|
isp->smk_inode = sbsp->smk_root;
|
|
isp->smk_flags |= SMK_INODE_INSTANT;
|
|
goto unlockandout;
|
|
}
|
|
|
|
/*
|
|
* This is pretty hackish.
|
|
* Casey says that we shouldn't have to do
|
|
* file system specific code, but it does help
|
|
* with keeping it simple.
|
|
*/
|
|
switch (sbp->s_magic) {
|
|
case SMACK_MAGIC:
|
|
case PIPEFS_MAGIC:
|
|
case SOCKFS_MAGIC:
|
|
case CGROUP_SUPER_MAGIC:
|
|
/*
|
|
* Casey says that it's a little embarrassing
|
|
* that the smack file system doesn't do
|
|
* extended attributes.
|
|
*
|
|
* Casey says pipes are easy (?)
|
|
*
|
|
* Socket access is controlled by the socket
|
|
* structures associated with the task involved.
|
|
*
|
|
* Cgroupfs is special
|
|
*/
|
|
final = smack_known_star.smk_known;
|
|
break;
|
|
case DEVPTS_SUPER_MAGIC:
|
|
/*
|
|
* devpts seems content with the label of the task.
|
|
* Programs that change smack have to treat the
|
|
* pty with respect.
|
|
*/
|
|
final = ckp->smk_known;
|
|
break;
|
|
case PROC_SUPER_MAGIC:
|
|
/*
|
|
* Casey says procfs appears not to care.
|
|
* The superblock default suffices.
|
|
*/
|
|
break;
|
|
case TMPFS_MAGIC:
|
|
/*
|
|
* Device labels should come from the filesystem,
|
|
* but watch out, because they're volitile,
|
|
* getting recreated on every reboot.
|
|
*/
|
|
final = smack_known_star.smk_known;
|
|
/*
|
|
* No break.
|
|
*
|
|
* If a smack value has been set we want to use it,
|
|
* but since tmpfs isn't giving us the opportunity
|
|
* to set mount options simulate setting the
|
|
* superblock default.
|
|
*/
|
|
default:
|
|
/*
|
|
* This isn't an understood special case.
|
|
* Get the value from the xattr.
|
|
*/
|
|
|
|
/*
|
|
* UNIX domain sockets use lower level socket data.
|
|
*/
|
|
if (S_ISSOCK(inode->i_mode)) {
|
|
final = smack_known_star.smk_known;
|
|
break;
|
|
}
|
|
/*
|
|
* No xattr support means, alas, no SMACK label.
|
|
* Use the aforeapplied default.
|
|
* It would be curious if the label of the task
|
|
* does not match that assigned.
|
|
*/
|
|
if (inode->i_op->getxattr == NULL)
|
|
break;
|
|
/*
|
|
* Get the dentry for xattr.
|
|
*/
|
|
dp = dget(opt_dentry);
|
|
skp = smk_fetch(XATTR_NAME_SMACK, inode, dp);
|
|
if (skp != NULL)
|
|
final = skp->smk_known;
|
|
|
|
/*
|
|
* Transmuting directory
|
|
*/
|
|
if (S_ISDIR(inode->i_mode)) {
|
|
/*
|
|
* If this is a new directory and the label was
|
|
* transmuted when the inode was initialized
|
|
* set the transmute attribute on the directory
|
|
* and mark the inode.
|
|
*
|
|
* If there is a transmute attribute on the
|
|
* directory mark the inode.
|
|
*/
|
|
if (isp->smk_flags & SMK_INODE_CHANGED) {
|
|
isp->smk_flags &= ~SMK_INODE_CHANGED;
|
|
rc = inode->i_op->setxattr(dp,
|
|
XATTR_NAME_SMACKTRANSMUTE,
|
|
TRANS_TRUE, TRANS_TRUE_SIZE,
|
|
0);
|
|
} else {
|
|
rc = inode->i_op->getxattr(dp,
|
|
XATTR_NAME_SMACKTRANSMUTE, trattr,
|
|
TRANS_TRUE_SIZE);
|
|
if (rc >= 0 && strncmp(trattr, TRANS_TRUE,
|
|
TRANS_TRUE_SIZE) != 0)
|
|
rc = -EINVAL;
|
|
}
|
|
if (rc >= 0)
|
|
transflag = SMK_INODE_TRANSMUTE;
|
|
}
|
|
/*
|
|
* Don't let the exec or mmap label be "*" or "@".
|
|
*/
|
|
skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
|
|
if (skp == &smack_known_star || skp == &smack_known_web)
|
|
skp = NULL;
|
|
isp->smk_task = skp;
|
|
skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
|
|
if (skp == &smack_known_star || skp == &smack_known_web)
|
|
skp = NULL;
|
|
isp->smk_mmap = skp;
|
|
|
|
dput(dp);
|
|
break;
|
|
}
|
|
|
|
if (final == NULL)
|
|
isp->smk_inode = ckp->smk_known;
|
|
else
|
|
isp->smk_inode = final;
|
|
|
|
isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
|
|
|
|
unlockandout:
|
|
mutex_unlock(&isp->smk_lock);
|
|
return;
|
|
}
|
|
|
|
/**
|
|
* smack_getprocattr - Smack process attribute access
|
|
* @p: the object task
|
|
* @name: the name of the attribute in /proc/.../attr
|
|
* @value: where to put the result
|
|
*
|
|
* Places a copy of the task Smack into value
|
|
*
|
|
* Returns the length of the smack label or an error code
|
|
*/
|
|
static int smack_getprocattr(struct task_struct *p, char *name, char **value)
|
|
{
|
|
struct smack_known *skp = smk_of_task(task_security(p));
|
|
char *cp;
|
|
int slen;
|
|
|
|
if (strcmp(name, "current") != 0)
|
|
return -EINVAL;
|
|
|
|
cp = kstrdup(skp->smk_known, GFP_KERNEL);
|
|
if (cp == NULL)
|
|
return -ENOMEM;
|
|
|
|
slen = strlen(cp);
|
|
*value = cp;
|
|
return slen;
|
|
}
|
|
|
|
/**
|
|
* smack_setprocattr - Smack process attribute setting
|
|
* @p: the object task
|
|
* @name: the name of the attribute in /proc/.../attr
|
|
* @value: the value to set
|
|
* @size: the size of the value
|
|
*
|
|
* Sets the Smack value of the task. Only setting self
|
|
* is permitted and only with privilege
|
|
*
|
|
* Returns the length of the smack label or an error code
|
|
*/
|
|
static int smack_setprocattr(struct task_struct *p, char *name,
|
|
void *value, size_t size)
|
|
{
|
|
struct task_smack *tsp;
|
|
struct cred *new;
|
|
struct smack_known *skp;
|
|
|
|
/*
|
|
* Changing another process' Smack value is too dangerous
|
|
* and supports no sane use case.
|
|
*/
|
|
if (p != current)
|
|
return -EPERM;
|
|
|
|
if (!smack_privileged(CAP_MAC_ADMIN))
|
|
return -EPERM;
|
|
|
|
if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
|
|
return -EINVAL;
|
|
|
|
if (strcmp(name, "current") != 0)
|
|
return -EINVAL;
|
|
|
|
skp = smk_import_entry(value, size);
|
|
if (skp == NULL)
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* No process is ever allowed the web ("@") label.
|
|
*/
|
|
if (skp == &smack_known_web)
|
|
return -EPERM;
|
|
|
|
new = prepare_creds();
|
|
if (new == NULL)
|
|
return -ENOMEM;
|
|
|
|
tsp = new->security;
|
|
tsp->smk_task = skp;
|
|
|
|
commit_creds(new);
|
|
return size;
|
|
}
|
|
|
|
/**
|
|
* smack_unix_stream_connect - Smack access on UDS
|
|
* @sock: one sock
|
|
* @other: the other sock
|
|
* @newsk: unused
|
|
*
|
|
* Return 0 if a subject with the smack of sock could access
|
|
* an object with the smack of other, otherwise an error code
|
|
*/
|
|
static int smack_unix_stream_connect(struct sock *sock,
|
|
struct sock *other, struct sock *newsk)
|
|
{
|
|
struct smack_known *skp;
|
|
struct smack_known *okp;
|
|
struct socket_smack *ssp = sock->sk_security;
|
|
struct socket_smack *osp = other->sk_security;
|
|
struct socket_smack *nsp = newsk->sk_security;
|
|
struct smk_audit_info ad;
|
|
int rc = 0;
|
|
#ifdef CONFIG_AUDIT
|
|
struct lsm_network_audit net;
|
|
#endif
|
|
|
|
if (!smack_privileged(CAP_MAC_OVERRIDE)) {
|
|
skp = ssp->smk_out;
|
|
okp = osp->smk_out;
|
|
#ifdef CONFIG_AUDIT
|
|
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
|
|
smk_ad_setfield_u_net_sk(&ad, other);
|
|
#endif
|
|
rc = smk_access(skp, okp->smk_known, MAY_WRITE, &ad);
|
|
if (rc == 0)
|
|
rc = smk_access(okp, okp->smk_known, MAY_WRITE, NULL);
|
|
}
|
|
|
|
/*
|
|
* Cross reference the peer labels for SO_PEERSEC.
|
|
*/
|
|
if (rc == 0) {
|
|
nsp->smk_packet = ssp->smk_out;
|
|
ssp->smk_packet = osp->smk_out;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_unix_may_send - Smack access on UDS
|
|
* @sock: one socket
|
|
* @other: the other socket
|
|
*
|
|
* Return 0 if a subject with the smack of sock could access
|
|
* an object with the smack of other, otherwise an error code
|
|
*/
|
|
static int smack_unix_may_send(struct socket *sock, struct socket *other)
|
|
{
|
|
struct socket_smack *ssp = sock->sk->sk_security;
|
|
struct socket_smack *osp = other->sk->sk_security;
|
|
struct smack_known *skp;
|
|
struct smk_audit_info ad;
|
|
|
|
#ifdef CONFIG_AUDIT
|
|
struct lsm_network_audit net;
|
|
|
|
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
|
|
smk_ad_setfield_u_net_sk(&ad, other->sk);
|
|
#endif
|
|
|
|
if (smack_privileged(CAP_MAC_OVERRIDE))
|
|
return 0;
|
|
|
|
skp = ssp->smk_out;
|
|
return smk_access(skp, osp->smk_in->smk_known, MAY_WRITE, &ad);
|
|
}
|
|
|
|
/**
|
|
* smack_socket_sendmsg - Smack check based on destination host
|
|
* @sock: the socket
|
|
* @msg: the message
|
|
* @size: the size of the message
|
|
*
|
|
* Return 0 if the current subject can write to the destination host.
|
|
* For IPv4 this is only a question if the destination is a single label host.
|
|
* For IPv6 this is a check against the label of the port.
|
|
*/
|
|
static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
|
|
int size)
|
|
{
|
|
struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
|
|
struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
|
|
int rc = 0;
|
|
|
|
/*
|
|
* Perfectly reasonable for this to be NULL
|
|
*/
|
|
if (sip == NULL)
|
|
return 0;
|
|
|
|
switch (sip->sin_family) {
|
|
case AF_INET:
|
|
rc = smack_netlabel_send(sock->sk, sip);
|
|
break;
|
|
case AF_INET6:
|
|
rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING);
|
|
break;
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
|
|
* @sap: netlabel secattr
|
|
* @ssp: socket security information
|
|
*
|
|
* Returns a pointer to a Smack label entry found on the label list.
|
|
*/
|
|
static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
|
|
struct socket_smack *ssp)
|
|
{
|
|
struct smack_known *skp;
|
|
int found = 0;
|
|
int acat;
|
|
int kcat;
|
|
|
|
if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
|
|
/*
|
|
* Looks like a CIPSO packet.
|
|
* If there are flags but no level netlabel isn't
|
|
* behaving the way we expect it to.
|
|
*
|
|
* Look it up in the label table
|
|
* Without guidance regarding the smack value
|
|
* for the packet fall back on the network
|
|
* ambient value.
|
|
*/
|
|
rcu_read_lock();
|
|
list_for_each_entry(skp, &smack_known_list, list) {
|
|
if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl)
|
|
continue;
|
|
/*
|
|
* Compare the catsets. Use the netlbl APIs.
|
|
*/
|
|
if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) {
|
|
if ((skp->smk_netlabel.flags &
|
|
NETLBL_SECATTR_MLS_CAT) == 0)
|
|
found = 1;
|
|
break;
|
|
}
|
|
for (acat = -1, kcat = -1; acat == kcat; ) {
|
|
acat = netlbl_secattr_catmap_walk(
|
|
sap->attr.mls.cat, acat + 1);
|
|
kcat = netlbl_secattr_catmap_walk(
|
|
skp->smk_netlabel.attr.mls.cat,
|
|
kcat + 1);
|
|
if (acat < 0 || kcat < 0)
|
|
break;
|
|
}
|
|
if (acat == kcat) {
|
|
found = 1;
|
|
break;
|
|
}
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
if (found)
|
|
return skp;
|
|
|
|
if (ssp != NULL && ssp->smk_in == &smack_known_star)
|
|
return &smack_known_web;
|
|
return &smack_known_star;
|
|
}
|
|
if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
|
|
/*
|
|
* Looks like a fallback, which gives us a secid.
|
|
*/
|
|
skp = smack_from_secid(sap->attr.secid);
|
|
/*
|
|
* This has got to be a bug because it is
|
|
* impossible to specify a fallback without
|
|
* specifying the label, which will ensure
|
|
* it has a secid, and the only way to get a
|
|
* secid is from a fallback.
|
|
*/
|
|
BUG_ON(skp == NULL);
|
|
return skp;
|
|
}
|
|
/*
|
|
* Without guidance regarding the smack value
|
|
* for the packet fall back on the network
|
|
* ambient value.
|
|
*/
|
|
return smack_net_ambient;
|
|
}
|
|
|
|
static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
|
|
{
|
|
u8 nexthdr;
|
|
int offset;
|
|
int proto = -EINVAL;
|
|
struct ipv6hdr _ipv6h;
|
|
struct ipv6hdr *ip6;
|
|
__be16 frag_off;
|
|
struct tcphdr _tcph, *th;
|
|
struct udphdr _udph, *uh;
|
|
struct dccp_hdr _dccph, *dh;
|
|
|
|
sip->sin6_port = 0;
|
|
|
|
offset = skb_network_offset(skb);
|
|
ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
|
|
if (ip6 == NULL)
|
|
return -EINVAL;
|
|
sip->sin6_addr = ip6->saddr;
|
|
|
|
nexthdr = ip6->nexthdr;
|
|
offset += sizeof(_ipv6h);
|
|
offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
|
|
if (offset < 0)
|
|
return -EINVAL;
|
|
|
|
proto = nexthdr;
|
|
switch (proto) {
|
|
case IPPROTO_TCP:
|
|
th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
|
|
if (th != NULL)
|
|
sip->sin6_port = th->source;
|
|
break;
|
|
case IPPROTO_UDP:
|
|
uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
|
|
if (uh != NULL)
|
|
sip->sin6_port = uh->source;
|
|
break;
|
|
case IPPROTO_DCCP:
|
|
dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
|
|
if (dh != NULL)
|
|
sip->sin6_port = dh->dccph_sport;
|
|
break;
|
|
}
|
|
return proto;
|
|
}
|
|
|
|
/**
|
|
* smack_socket_sock_rcv_skb - Smack packet delivery access check
|
|
* @sk: socket
|
|
* @skb: packet
|
|
*
|
|
* Returns 0 if the packet should be delivered, an error code otherwise
|
|
*/
|
|
static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct netlbl_lsm_secattr secattr;
|
|
struct socket_smack *ssp = sk->sk_security;
|
|
struct smack_known *skp;
|
|
struct sockaddr_in6 sadd;
|
|
int rc = 0;
|
|
struct smk_audit_info ad;
|
|
#ifdef CONFIG_AUDIT
|
|
struct lsm_network_audit net;
|
|
#endif
|
|
switch (sk->sk_family) {
|
|
case PF_INET:
|
|
/*
|
|
* Translate what netlabel gave us.
|
|
*/
|
|
netlbl_secattr_init(&secattr);
|
|
|
|
rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
|
|
if (rc == 0)
|
|
skp = smack_from_secattr(&secattr, ssp);
|
|
else
|
|
skp = smack_net_ambient;
|
|
|
|
netlbl_secattr_destroy(&secattr);
|
|
|
|
#ifdef CONFIG_AUDIT
|
|
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
|
|
ad.a.u.net->family = sk->sk_family;
|
|
ad.a.u.net->netif = skb->skb_iif;
|
|
ipv4_skb_to_auditdata(skb, &ad.a, NULL);
|
|
#endif
|
|
/*
|
|
* Receiving a packet requires that the other end
|
|
* be able to write here. Read access is not required.
|
|
* This is the simplist possible security model
|
|
* for networking.
|
|
*/
|
|
rc = smk_access(skp, ssp->smk_in->smk_known, MAY_WRITE, &ad);
|
|
if (rc != 0)
|
|
netlbl_skbuff_err(skb, rc, 0);
|
|
break;
|
|
case PF_INET6:
|
|
rc = smk_skb_to_addr_ipv6(skb, &sadd);
|
|
if (rc == IPPROTO_UDP || rc == IPPROTO_TCP)
|
|
rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING);
|
|
else
|
|
rc = 0;
|
|
break;
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_socket_getpeersec_stream - pull in packet label
|
|
* @sock: the socket
|
|
* @optval: user's destination
|
|
* @optlen: size thereof
|
|
* @len: max thereof
|
|
*
|
|
* returns zero on success, an error code otherwise
|
|
*/
|
|
static int smack_socket_getpeersec_stream(struct socket *sock,
|
|
char __user *optval,
|
|
int __user *optlen, unsigned len)
|
|
{
|
|
struct socket_smack *ssp;
|
|
char *rcp = "";
|
|
int slen = 1;
|
|
int rc = 0;
|
|
|
|
ssp = sock->sk->sk_security;
|
|
if (ssp->smk_packet != NULL) {
|
|
rcp = ssp->smk_packet->smk_known;
|
|
slen = strlen(rcp) + 1;
|
|
}
|
|
|
|
if (slen > len)
|
|
rc = -ERANGE;
|
|
else if (copy_to_user(optval, rcp, slen) != 0)
|
|
rc = -EFAULT;
|
|
|
|
if (put_user(slen, optlen) != 0)
|
|
rc = -EFAULT;
|
|
|
|
return rc;
|
|
}
|
|
|
|
|
|
/**
|
|
* smack_socket_getpeersec_dgram - pull in packet label
|
|
* @sock: the peer socket
|
|
* @skb: packet data
|
|
* @secid: pointer to where to put the secid of the packet
|
|
*
|
|
* Sets the netlabel socket state on sk from parent
|
|
*/
|
|
static int smack_socket_getpeersec_dgram(struct socket *sock,
|
|
struct sk_buff *skb, u32 *secid)
|
|
|
|
{
|
|
struct netlbl_lsm_secattr secattr;
|
|
struct socket_smack *ssp = NULL;
|
|
struct smack_known *skp;
|
|
int family = PF_UNSPEC;
|
|
u32 s = 0; /* 0 is the invalid secid */
|
|
int rc;
|
|
|
|
if (skb != NULL) {
|
|
if (skb->protocol == htons(ETH_P_IP))
|
|
family = PF_INET;
|
|
else if (skb->protocol == htons(ETH_P_IPV6))
|
|
family = PF_INET6;
|
|
}
|
|
if (family == PF_UNSPEC && sock != NULL)
|
|
family = sock->sk->sk_family;
|
|
|
|
if (family == PF_UNIX) {
|
|
ssp = sock->sk->sk_security;
|
|
s = ssp->smk_out->smk_secid;
|
|
} else if (family == PF_INET || family == PF_INET6) {
|
|
/*
|
|
* Translate what netlabel gave us.
|
|
*/
|
|
if (sock != NULL && sock->sk != NULL)
|
|
ssp = sock->sk->sk_security;
|
|
netlbl_secattr_init(&secattr);
|
|
rc = netlbl_skbuff_getattr(skb, family, &secattr);
|
|
if (rc == 0) {
|
|
skp = smack_from_secattr(&secattr, ssp);
|
|
s = skp->smk_secid;
|
|
}
|
|
netlbl_secattr_destroy(&secattr);
|
|
}
|
|
*secid = s;
|
|
if (s == 0)
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_sock_graft - Initialize a newly created socket with an existing sock
|
|
* @sk: child sock
|
|
* @parent: parent socket
|
|
*
|
|
* Set the smk_{in,out} state of an existing sock based on the process that
|
|
* is creating the new socket.
|
|
*/
|
|
static void smack_sock_graft(struct sock *sk, struct socket *parent)
|
|
{
|
|
struct socket_smack *ssp;
|
|
struct smack_known *skp = smk_of_current();
|
|
|
|
if (sk == NULL ||
|
|
(sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
|
|
return;
|
|
|
|
ssp = sk->sk_security;
|
|
ssp->smk_in = skp;
|
|
ssp->smk_out = skp;
|
|
/* cssp->smk_packet is already set in smack_inet_csk_clone() */
|
|
}
|
|
|
|
/**
|
|
* smack_inet_conn_request - Smack access check on connect
|
|
* @sk: socket involved
|
|
* @skb: packet
|
|
* @req: unused
|
|
*
|
|
* Returns 0 if a task with the packet label could write to
|
|
* the socket, otherwise an error code
|
|
*/
|
|
static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
|
|
struct request_sock *req)
|
|
{
|
|
u16 family = sk->sk_family;
|
|
struct smack_known *skp;
|
|
struct socket_smack *ssp = sk->sk_security;
|
|
struct netlbl_lsm_secattr secattr;
|
|
struct sockaddr_in addr;
|
|
struct iphdr *hdr;
|
|
char *hsp;
|
|
int rc;
|
|
struct smk_audit_info ad;
|
|
#ifdef CONFIG_AUDIT
|
|
struct lsm_network_audit net;
|
|
#endif
|
|
|
|
if (family == PF_INET6) {
|
|
/*
|
|
* Handle mapped IPv4 packets arriving
|
|
* via IPv6 sockets. Don't set up netlabel
|
|
* processing on IPv6.
|
|
*/
|
|
if (skb->protocol == htons(ETH_P_IP))
|
|
family = PF_INET;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
netlbl_secattr_init(&secattr);
|
|
rc = netlbl_skbuff_getattr(skb, family, &secattr);
|
|
if (rc == 0)
|
|
skp = smack_from_secattr(&secattr, ssp);
|
|
else
|
|
skp = &smack_known_huh;
|
|
netlbl_secattr_destroy(&secattr);
|
|
|
|
#ifdef CONFIG_AUDIT
|
|
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
|
|
ad.a.u.net->family = family;
|
|
ad.a.u.net->netif = skb->skb_iif;
|
|
ipv4_skb_to_auditdata(skb, &ad.a, NULL);
|
|
#endif
|
|
/*
|
|
* Receiving a packet requires that the other end be able to write
|
|
* here. Read access is not required.
|
|
*/
|
|
rc = smk_access(skp, ssp->smk_in->smk_known, MAY_WRITE, &ad);
|
|
if (rc != 0)
|
|
return rc;
|
|
|
|
/*
|
|
* Save the peer's label in the request_sock so we can later setup
|
|
* smk_packet in the child socket so that SO_PEERCRED can report it.
|
|
*/
|
|
req->peer_secid = skp->smk_secid;
|
|
|
|
/*
|
|
* We need to decide if we want to label the incoming connection here
|
|
* if we do we only need to label the request_sock and the stack will
|
|
* propagate the wire-label to the sock when it is created.
|
|
*/
|
|
hdr = ip_hdr(skb);
|
|
addr.sin_addr.s_addr = hdr->saddr;
|
|
rcu_read_lock();
|
|
hsp = smack_host_label(&addr);
|
|
rcu_read_unlock();
|
|
|
|
if (hsp == NULL)
|
|
rc = netlbl_req_setattr(req, &skp->smk_netlabel);
|
|
else
|
|
netlbl_req_delattr(req);
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_inet_csk_clone - Copy the connection information to the new socket
|
|
* @sk: the new socket
|
|
* @req: the connection's request_sock
|
|
*
|
|
* Transfer the connection's peer label to the newly created socket.
|
|
*/
|
|
static void smack_inet_csk_clone(struct sock *sk,
|
|
const struct request_sock *req)
|
|
{
|
|
struct socket_smack *ssp = sk->sk_security;
|
|
struct smack_known *skp;
|
|
|
|
if (req->peer_secid != 0) {
|
|
skp = smack_from_secid(req->peer_secid);
|
|
ssp->smk_packet = skp;
|
|
} else
|
|
ssp->smk_packet = NULL;
|
|
}
|
|
|
|
/*
|
|
* Key management security hooks
|
|
*
|
|
* Casey has not tested key support very heavily.
|
|
* The permission check is most likely too restrictive.
|
|
* If you care about keys please have a look.
|
|
*/
|
|
#ifdef CONFIG_KEYS
|
|
|
|
/**
|
|
* smack_key_alloc - Set the key security blob
|
|
* @key: object
|
|
* @cred: the credentials to use
|
|
* @flags: unused
|
|
*
|
|
* No allocation required
|
|
*
|
|
* Returns 0
|
|
*/
|
|
static int smack_key_alloc(struct key *key, const struct cred *cred,
|
|
unsigned long flags)
|
|
{
|
|
struct smack_known *skp = smk_of_task(cred->security);
|
|
|
|
key->security = skp->smk_known;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_key_free - Clear the key security blob
|
|
* @key: the object
|
|
*
|
|
* Clear the blob pointer
|
|
*/
|
|
static void smack_key_free(struct key *key)
|
|
{
|
|
key->security = NULL;
|
|
}
|
|
|
|
/*
|
|
* smack_key_permission - Smack access on a key
|
|
* @key_ref: gets to the object
|
|
* @cred: the credentials to use
|
|
* @perm: unused
|
|
*
|
|
* Return 0 if the task has read and write to the object,
|
|
* an error code otherwise
|
|
*/
|
|
static int smack_key_permission(key_ref_t key_ref,
|
|
const struct cred *cred, unsigned perm)
|
|
{
|
|
struct key *keyp;
|
|
struct smk_audit_info ad;
|
|
struct smack_known *tkp = smk_of_task(cred->security);
|
|
int request = 0;
|
|
|
|
keyp = key_ref_to_ptr(key_ref);
|
|
if (keyp == NULL)
|
|
return -EINVAL;
|
|
/*
|
|
* If the key hasn't been initialized give it access so that
|
|
* it may do so.
|
|
*/
|
|
if (keyp->security == NULL)
|
|
return 0;
|
|
/*
|
|
* This should not occur
|
|
*/
|
|
if (tkp == NULL)
|
|
return -EACCES;
|
|
#ifdef CONFIG_AUDIT
|
|
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
|
|
ad.a.u.key_struct.key = keyp->serial;
|
|
ad.a.u.key_struct.key_desc = keyp->description;
|
|
#endif
|
|
if (perm & KEY_NEED_READ)
|
|
request = MAY_READ;
|
|
if (perm & (KEY_NEED_WRITE | KEY_NEED_LINK | KEY_NEED_SETATTR))
|
|
request = MAY_WRITE;
|
|
return smk_access(tkp, keyp->security, request, &ad);
|
|
}
|
|
#endif /* CONFIG_KEYS */
|
|
|
|
/*
|
|
* Smack Audit hooks
|
|
*
|
|
* Audit requires a unique representation of each Smack specific
|
|
* rule. This unique representation is used to distinguish the
|
|
* object to be audited from remaining kernel objects and also
|
|
* works as a glue between the audit hooks.
|
|
*
|
|
* Since repository entries are added but never deleted, we'll use
|
|
* the smack_known label address related to the given audit rule as
|
|
* the needed unique representation. This also better fits the smack
|
|
* model where nearly everything is a label.
|
|
*/
|
|
#ifdef CONFIG_AUDIT
|
|
|
|
/**
|
|
* smack_audit_rule_init - Initialize a smack audit rule
|
|
* @field: audit rule fields given from user-space (audit.h)
|
|
* @op: required testing operator (=, !=, >, <, ...)
|
|
* @rulestr: smack label to be audited
|
|
* @vrule: pointer to save our own audit rule representation
|
|
*
|
|
* Prepare to audit cases where (@field @op @rulestr) is true.
|
|
* The label to be audited is created if necessay.
|
|
*/
|
|
static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
|
|
{
|
|
char **rule = (char **)vrule;
|
|
*rule = NULL;
|
|
|
|
if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
|
|
return -EINVAL;
|
|
|
|
if (op != Audit_equal && op != Audit_not_equal)
|
|
return -EINVAL;
|
|
|
|
*rule = smk_import(rulestr, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_audit_rule_known - Distinguish Smack audit rules
|
|
* @krule: rule of interest, in Audit kernel representation format
|
|
*
|
|
* This is used to filter Smack rules from remaining Audit ones.
|
|
* If it's proved that this rule belongs to us, the
|
|
* audit_rule_match hook will be called to do the final judgement.
|
|
*/
|
|
static int smack_audit_rule_known(struct audit_krule *krule)
|
|
{
|
|
struct audit_field *f;
|
|
int i;
|
|
|
|
for (i = 0; i < krule->field_count; i++) {
|
|
f = &krule->fields[i];
|
|
|
|
if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_audit_rule_match - Audit given object ?
|
|
* @secid: security id for identifying the object to test
|
|
* @field: audit rule flags given from user-space
|
|
* @op: required testing operator
|
|
* @vrule: smack internal rule presentation
|
|
* @actx: audit context associated with the check
|
|
*
|
|
* The core Audit hook. It's used to take the decision of
|
|
* whether to audit or not to audit a given object.
|
|
*/
|
|
static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
|
|
struct audit_context *actx)
|
|
{
|
|
struct smack_known *skp;
|
|
char *rule = vrule;
|
|
|
|
if (unlikely(!rule)) {
|
|
WARN_ONCE(1, "Smack: missing rule\n");
|
|
return -ENOENT;
|
|
}
|
|
|
|
if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
|
|
return 0;
|
|
|
|
skp = smack_from_secid(secid);
|
|
|
|
/*
|
|
* No need to do string comparisons. If a match occurs,
|
|
* both pointers will point to the same smack_known
|
|
* label.
|
|
*/
|
|
if (op == Audit_equal)
|
|
return (rule == skp->smk_known);
|
|
if (op == Audit_not_equal)
|
|
return (rule != skp->smk_known);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_audit_rule_free - free smack rule representation
|
|
* @vrule: rule to be freed.
|
|
*
|
|
* No memory was allocated.
|
|
*/
|
|
static void smack_audit_rule_free(void *vrule)
|
|
{
|
|
/* No-op */
|
|
}
|
|
|
|
#endif /* CONFIG_AUDIT */
|
|
|
|
/**
|
|
* smack_ismaclabel - check if xattr @name references a smack MAC label
|
|
* @name: Full xattr name to check.
|
|
*/
|
|
static int smack_ismaclabel(const char *name)
|
|
{
|
|
return (strcmp(name, XATTR_SMACK_SUFFIX) == 0);
|
|
}
|
|
|
|
|
|
/**
|
|
* smack_secid_to_secctx - return the smack label for a secid
|
|
* @secid: incoming integer
|
|
* @secdata: destination
|
|
* @seclen: how long it is
|
|
*
|
|
* Exists for networking code.
|
|
*/
|
|
static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
|
|
{
|
|
struct smack_known *skp = smack_from_secid(secid);
|
|
|
|
if (secdata)
|
|
*secdata = skp->smk_known;
|
|
*seclen = strlen(skp->smk_known);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_secctx_to_secid - return the secid for a smack label
|
|
* @secdata: smack label
|
|
* @seclen: how long result is
|
|
* @secid: outgoing integer
|
|
*
|
|
* Exists for audit and networking code.
|
|
*/
|
|
static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
|
|
{
|
|
*secid = smack_to_secid(secdata);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_release_secctx - don't do anything.
|
|
* @secdata: unused
|
|
* @seclen: unused
|
|
*
|
|
* Exists to make sure nothing gets done, and properly
|
|
*/
|
|
static void smack_release_secctx(char *secdata, u32 seclen)
|
|
{
|
|
}
|
|
|
|
static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
|
|
{
|
|
return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0);
|
|
}
|
|
|
|
static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
|
|
{
|
|
return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0);
|
|
}
|
|
|
|
static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
|
|
{
|
|
int len = 0;
|
|
len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true);
|
|
|
|
if (len < 0)
|
|
return len;
|
|
*ctxlen = len;
|
|
return 0;
|
|
}
|
|
|
|
struct security_operations smack_ops = {
|
|
.name = "smack",
|
|
|
|
.ptrace_access_check = smack_ptrace_access_check,
|
|
.ptrace_traceme = smack_ptrace_traceme,
|
|
.syslog = smack_syslog,
|
|
|
|
.sb_alloc_security = smack_sb_alloc_security,
|
|
.sb_free_security = smack_sb_free_security,
|
|
.sb_copy_data = smack_sb_copy_data,
|
|
.sb_kern_mount = smack_sb_kern_mount,
|
|
.sb_statfs = smack_sb_statfs,
|
|
|
|
.bprm_set_creds = smack_bprm_set_creds,
|
|
.bprm_committing_creds = smack_bprm_committing_creds,
|
|
.bprm_secureexec = smack_bprm_secureexec,
|
|
|
|
.inode_alloc_security = smack_inode_alloc_security,
|
|
.inode_free_security = smack_inode_free_security,
|
|
.inode_init_security = smack_inode_init_security,
|
|
.inode_link = smack_inode_link,
|
|
.inode_unlink = smack_inode_unlink,
|
|
.inode_rmdir = smack_inode_rmdir,
|
|
.inode_rename = smack_inode_rename,
|
|
.inode_permission = smack_inode_permission,
|
|
.inode_setattr = smack_inode_setattr,
|
|
.inode_getattr = smack_inode_getattr,
|
|
.inode_setxattr = smack_inode_setxattr,
|
|
.inode_post_setxattr = smack_inode_post_setxattr,
|
|
.inode_getxattr = smack_inode_getxattr,
|
|
.inode_removexattr = smack_inode_removexattr,
|
|
.inode_getsecurity = smack_inode_getsecurity,
|
|
.inode_setsecurity = smack_inode_setsecurity,
|
|
.inode_listsecurity = smack_inode_listsecurity,
|
|
.inode_getsecid = smack_inode_getsecid,
|
|
|
|
.file_permission = smack_file_permission,
|
|
.file_alloc_security = smack_file_alloc_security,
|
|
.file_free_security = smack_file_free_security,
|
|
.file_ioctl = smack_file_ioctl,
|
|
.file_lock = smack_file_lock,
|
|
.file_fcntl = smack_file_fcntl,
|
|
.mmap_file = smack_mmap_file,
|
|
.mmap_addr = cap_mmap_addr,
|
|
.file_set_fowner = smack_file_set_fowner,
|
|
.file_send_sigiotask = smack_file_send_sigiotask,
|
|
.file_receive = smack_file_receive,
|
|
|
|
.file_open = smack_file_open,
|
|
|
|
.cred_alloc_blank = smack_cred_alloc_blank,
|
|
.cred_free = smack_cred_free,
|
|
.cred_prepare = smack_cred_prepare,
|
|
.cred_transfer = smack_cred_transfer,
|
|
.kernel_act_as = smack_kernel_act_as,
|
|
.kernel_create_files_as = smack_kernel_create_files_as,
|
|
.task_setpgid = smack_task_setpgid,
|
|
.task_getpgid = smack_task_getpgid,
|
|
.task_getsid = smack_task_getsid,
|
|
.task_getsecid = smack_task_getsecid,
|
|
.task_setnice = smack_task_setnice,
|
|
.task_setioprio = smack_task_setioprio,
|
|
.task_getioprio = smack_task_getioprio,
|
|
.task_setscheduler = smack_task_setscheduler,
|
|
.task_getscheduler = smack_task_getscheduler,
|
|
.task_movememory = smack_task_movememory,
|
|
.task_kill = smack_task_kill,
|
|
.task_wait = smack_task_wait,
|
|
.task_to_inode = smack_task_to_inode,
|
|
|
|
.ipc_permission = smack_ipc_permission,
|
|
.ipc_getsecid = smack_ipc_getsecid,
|
|
|
|
.msg_msg_alloc_security = smack_msg_msg_alloc_security,
|
|
.msg_msg_free_security = smack_msg_msg_free_security,
|
|
|
|
.msg_queue_alloc_security = smack_msg_queue_alloc_security,
|
|
.msg_queue_free_security = smack_msg_queue_free_security,
|
|
.msg_queue_associate = smack_msg_queue_associate,
|
|
.msg_queue_msgctl = smack_msg_queue_msgctl,
|
|
.msg_queue_msgsnd = smack_msg_queue_msgsnd,
|
|
.msg_queue_msgrcv = smack_msg_queue_msgrcv,
|
|
|
|
.shm_alloc_security = smack_shm_alloc_security,
|
|
.shm_free_security = smack_shm_free_security,
|
|
.shm_associate = smack_shm_associate,
|
|
.shm_shmctl = smack_shm_shmctl,
|
|
.shm_shmat = smack_shm_shmat,
|
|
|
|
.sem_alloc_security = smack_sem_alloc_security,
|
|
.sem_free_security = smack_sem_free_security,
|
|
.sem_associate = smack_sem_associate,
|
|
.sem_semctl = smack_sem_semctl,
|
|
.sem_semop = smack_sem_semop,
|
|
|
|
.d_instantiate = smack_d_instantiate,
|
|
|
|
.getprocattr = smack_getprocattr,
|
|
.setprocattr = smack_setprocattr,
|
|
|
|
.unix_stream_connect = smack_unix_stream_connect,
|
|
.unix_may_send = smack_unix_may_send,
|
|
|
|
.socket_post_create = smack_socket_post_create,
|
|
.socket_bind = smack_socket_bind,
|
|
.socket_connect = smack_socket_connect,
|
|
.socket_sendmsg = smack_socket_sendmsg,
|
|
.socket_sock_rcv_skb = smack_socket_sock_rcv_skb,
|
|
.socket_getpeersec_stream = smack_socket_getpeersec_stream,
|
|
.socket_getpeersec_dgram = smack_socket_getpeersec_dgram,
|
|
.sk_alloc_security = smack_sk_alloc_security,
|
|
.sk_free_security = smack_sk_free_security,
|
|
.sock_graft = smack_sock_graft,
|
|
.inet_conn_request = smack_inet_conn_request,
|
|
.inet_csk_clone = smack_inet_csk_clone,
|
|
|
|
/* key management security hooks */
|
|
#ifdef CONFIG_KEYS
|
|
.key_alloc = smack_key_alloc,
|
|
.key_free = smack_key_free,
|
|
.key_permission = smack_key_permission,
|
|
#endif /* CONFIG_KEYS */
|
|
|
|
/* Audit hooks */
|
|
#ifdef CONFIG_AUDIT
|
|
.audit_rule_init = smack_audit_rule_init,
|
|
.audit_rule_known = smack_audit_rule_known,
|
|
.audit_rule_match = smack_audit_rule_match,
|
|
.audit_rule_free = smack_audit_rule_free,
|
|
#endif /* CONFIG_AUDIT */
|
|
|
|
.ismaclabel = smack_ismaclabel,
|
|
.secid_to_secctx = smack_secid_to_secctx,
|
|
.secctx_to_secid = smack_secctx_to_secid,
|
|
.release_secctx = smack_release_secctx,
|
|
.inode_notifysecctx = smack_inode_notifysecctx,
|
|
.inode_setsecctx = smack_inode_setsecctx,
|
|
.inode_getsecctx = smack_inode_getsecctx,
|
|
};
|
|
|
|
|
|
static __init void init_smack_known_list(void)
|
|
{
|
|
/*
|
|
* Initialize rule list locks
|
|
*/
|
|
mutex_init(&smack_known_huh.smk_rules_lock);
|
|
mutex_init(&smack_known_hat.smk_rules_lock);
|
|
mutex_init(&smack_known_floor.smk_rules_lock);
|
|
mutex_init(&smack_known_star.smk_rules_lock);
|
|
mutex_init(&smack_known_invalid.smk_rules_lock);
|
|
mutex_init(&smack_known_web.smk_rules_lock);
|
|
/*
|
|
* Initialize rule lists
|
|
*/
|
|
INIT_LIST_HEAD(&smack_known_huh.smk_rules);
|
|
INIT_LIST_HEAD(&smack_known_hat.smk_rules);
|
|
INIT_LIST_HEAD(&smack_known_star.smk_rules);
|
|
INIT_LIST_HEAD(&smack_known_floor.smk_rules);
|
|
INIT_LIST_HEAD(&smack_known_invalid.smk_rules);
|
|
INIT_LIST_HEAD(&smack_known_web.smk_rules);
|
|
/*
|
|
* Create the known labels list
|
|
*/
|
|
smk_insert_entry(&smack_known_huh);
|
|
smk_insert_entry(&smack_known_hat);
|
|
smk_insert_entry(&smack_known_star);
|
|
smk_insert_entry(&smack_known_floor);
|
|
smk_insert_entry(&smack_known_invalid);
|
|
smk_insert_entry(&smack_known_web);
|
|
}
|
|
|
|
/**
|
|
* smack_init - initialize the smack system
|
|
*
|
|
* Returns 0
|
|
*/
|
|
static __init int smack_init(void)
|
|
{
|
|
struct cred *cred;
|
|
struct task_smack *tsp;
|
|
|
|
if (!security_module_enable(&smack_ops))
|
|
return 0;
|
|
|
|
tsp = new_task_smack(&smack_known_floor, &smack_known_floor,
|
|
GFP_KERNEL);
|
|
if (tsp == NULL)
|
|
return -ENOMEM;
|
|
|
|
printk(KERN_INFO "Smack: Initializing.\n");
|
|
|
|
/*
|
|
* Set the security state for the initial task.
|
|
*/
|
|
cred = (struct cred *) current->cred;
|
|
cred->security = tsp;
|
|
|
|
/* initialize the smack_known_list */
|
|
init_smack_known_list();
|
|
|
|
/*
|
|
* Register with LSM
|
|
*/
|
|
if (register_security(&smack_ops))
|
|
panic("smack: Unable to register with kernel.\n");
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Smack requires early initialization in order to label
|
|
* all processes and objects when they are created.
|
|
*/
|
|
security_initcall(smack_init);
|