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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-21 16:29:59 +00:00
![Linus Torvalds](/assets/img/avatar_default.png)
Pull second vfs pile from Al Viro: "The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the deadlock reproduced by xfstests 068), symlink and hardlink restriction patches, plus assorted cleanups and fixes. Note that another fsfreeze deadlock (emergency thaw one) is *not* dealt with - the series by Fernando conflicts a lot with Jan's, breaks userland ABI (FIFREEZE semantics gets changed) and trades the deadlock for massive vfsmount leak; this is going to be handled next cycle. There probably will be another pull request, but that stuff won't be in it." Fix up trivial conflicts due to unrelated changes next to each other in drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c} * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits) delousing target_core_file a bit Documentation: Correct s_umount state for freeze_fs/unfreeze_fs fs: Remove old freezing mechanism ext2: Implement freezing btrfs: Convert to new freezing mechanism nilfs2: Convert to new freezing mechanism ntfs: Convert to new freezing mechanism fuse: Convert to new freezing mechanism gfs2: Convert to new freezing mechanism ocfs2: Convert to new freezing mechanism xfs: Convert to new freezing code ext4: Convert to new freezing mechanism fs: Protect write paths by sb_start_write - sb_end_write fs: Skip atime update on frozen filesystem fs: Add freezing handling to mnt_want_write() / mnt_drop_write() fs: Improve filesystem freezing handling switch the protection of percpu_counter list to spinlock nfsd: Push mnt_want_write() outside of i_mutex btrfs: Push mnt_want_write() outside of i_mutex fat: Push mnt_want_write() outside of i_mutex ...
1565 lines
41 KiB
C
1565 lines
41 KiB
C
/* audit.c -- Auditing support
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* Gateway between the kernel (e.g., selinux) and the user-space audit daemon.
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* System-call specific features have moved to auditsc.c
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*
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* Copyright 2003-2007 Red Hat Inc., Durham, North Carolina.
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* All Rights Reserved.
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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 as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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* Written by Rickard E. (Rik) Faith <faith@redhat.com>
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*
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* Goals: 1) Integrate fully with Security Modules.
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* 2) Minimal run-time overhead:
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* a) Minimal when syscall auditing is disabled (audit_enable=0).
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* b) Small when syscall auditing is enabled and no audit record
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* is generated (defer as much work as possible to record
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* generation time):
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* i) context is allocated,
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* ii) names from getname are stored without a copy, and
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* iii) inode information stored from path_lookup.
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* 3) Ability to disable syscall auditing at boot time (audit=0).
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* 4) Usable by other parts of the kernel (if audit_log* is called,
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* then a syscall record will be generated automatically for the
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* current syscall).
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* 5) Netlink interface to user-space.
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* 6) Support low-overhead kernel-based filtering to minimize the
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* information that must be passed to user-space.
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*
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* Example user-space utilities: http://people.redhat.com/sgrubb/audit/
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*/
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#include <linux/init.h>
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#include <asm/types.h>
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#include <linux/atomic.h>
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#include <linux/mm.h>
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#include <linux/export.h>
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#include <linux/slab.h>
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#include <linux/err.h>
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#include <linux/kthread.h>
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#include <linux/audit.h>
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#include <net/sock.h>
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#include <net/netlink.h>
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#include <linux/skbuff.h>
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#ifdef CONFIG_SECURITY
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#include <linux/security.h>
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#endif
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#include <linux/netlink.h>
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#include <linux/freezer.h>
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#include <linux/tty.h>
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#include "audit.h"
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/* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
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* (Initialization happens after skb_init is called.) */
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#define AUDIT_DISABLED -1
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#define AUDIT_UNINITIALIZED 0
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#define AUDIT_INITIALIZED 1
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static int audit_initialized;
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#define AUDIT_OFF 0
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#define AUDIT_ON 1
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#define AUDIT_LOCKED 2
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int audit_enabled;
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int audit_ever_enabled;
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EXPORT_SYMBOL_GPL(audit_enabled);
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/* Default state when kernel boots without any parameters. */
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static int audit_default;
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/* If auditing cannot proceed, audit_failure selects what happens. */
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static int audit_failure = AUDIT_FAIL_PRINTK;
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/*
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* If audit records are to be written to the netlink socket, audit_pid
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* contains the pid of the auditd process and audit_nlk_pid contains
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* the pid to use to send netlink messages to that process.
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*/
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int audit_pid;
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static int audit_nlk_pid;
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/* If audit_rate_limit is non-zero, limit the rate of sending audit records
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* to that number per second. This prevents DoS attacks, but results in
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* audit records being dropped. */
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static int audit_rate_limit;
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/* Number of outstanding audit_buffers allowed. */
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static int audit_backlog_limit = 64;
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static int audit_backlog_wait_time = 60 * HZ;
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static int audit_backlog_wait_overflow = 0;
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/* The identity of the user shutting down the audit system. */
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uid_t audit_sig_uid = -1;
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pid_t audit_sig_pid = -1;
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u32 audit_sig_sid = 0;
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/* Records can be lost in several ways:
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0) [suppressed in audit_alloc]
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1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
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2) out of memory in audit_log_move [alloc_skb]
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3) suppressed due to audit_rate_limit
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4) suppressed due to audit_backlog_limit
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*/
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static atomic_t audit_lost = ATOMIC_INIT(0);
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/* The netlink socket. */
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static struct sock *audit_sock;
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/* Hash for inode-based rules */
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struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
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/* The audit_freelist is a list of pre-allocated audit buffers (if more
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* than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
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* being placed on the freelist). */
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static DEFINE_SPINLOCK(audit_freelist_lock);
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static int audit_freelist_count;
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static LIST_HEAD(audit_freelist);
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static struct sk_buff_head audit_skb_queue;
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/* queue of skbs to send to auditd when/if it comes back */
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static struct sk_buff_head audit_skb_hold_queue;
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static struct task_struct *kauditd_task;
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static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
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static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
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/* Serialize requests from userspace. */
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DEFINE_MUTEX(audit_cmd_mutex);
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/* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
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* audit records. Since printk uses a 1024 byte buffer, this buffer
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* should be at least that large. */
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#define AUDIT_BUFSIZ 1024
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/* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the
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* audit_freelist. Doing so eliminates many kmalloc/kfree calls. */
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#define AUDIT_MAXFREE (2*NR_CPUS)
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/* The audit_buffer is used when formatting an audit record. The caller
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* locks briefly to get the record off the freelist or to allocate the
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* buffer, and locks briefly to send the buffer to the netlink layer or
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* to place it on a transmit queue. Multiple audit_buffers can be in
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* use simultaneously. */
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struct audit_buffer {
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struct list_head list;
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struct sk_buff *skb; /* formatted skb ready to send */
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struct audit_context *ctx; /* NULL or associated context */
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gfp_t gfp_mask;
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};
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struct audit_reply {
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int pid;
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struct sk_buff *skb;
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};
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static void audit_set_pid(struct audit_buffer *ab, pid_t pid)
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{
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if (ab) {
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struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
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nlh->nlmsg_pid = pid;
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}
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}
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void audit_panic(const char *message)
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{
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switch (audit_failure)
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{
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case AUDIT_FAIL_SILENT:
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break;
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case AUDIT_FAIL_PRINTK:
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if (printk_ratelimit())
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printk(KERN_ERR "audit: %s\n", message);
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break;
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case AUDIT_FAIL_PANIC:
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/* test audit_pid since printk is always losey, why bother? */
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if (audit_pid)
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panic("audit: %s\n", message);
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break;
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}
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}
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static inline int audit_rate_check(void)
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{
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static unsigned long last_check = 0;
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static int messages = 0;
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static DEFINE_SPINLOCK(lock);
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unsigned long flags;
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unsigned long now;
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unsigned long elapsed;
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int retval = 0;
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if (!audit_rate_limit) return 1;
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spin_lock_irqsave(&lock, flags);
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if (++messages < audit_rate_limit) {
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retval = 1;
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} else {
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now = jiffies;
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elapsed = now - last_check;
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if (elapsed > HZ) {
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last_check = now;
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messages = 0;
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retval = 1;
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}
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}
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spin_unlock_irqrestore(&lock, flags);
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return retval;
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}
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/**
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* audit_log_lost - conditionally log lost audit message event
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* @message: the message stating reason for lost audit message
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*
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* Emit at least 1 message per second, even if audit_rate_check is
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* throttling.
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* Always increment the lost messages counter.
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*/
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void audit_log_lost(const char *message)
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{
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static unsigned long last_msg = 0;
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static DEFINE_SPINLOCK(lock);
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unsigned long flags;
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unsigned long now;
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int print;
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atomic_inc(&audit_lost);
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print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
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if (!print) {
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spin_lock_irqsave(&lock, flags);
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now = jiffies;
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if (now - last_msg > HZ) {
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print = 1;
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last_msg = now;
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}
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spin_unlock_irqrestore(&lock, flags);
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}
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if (print) {
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if (printk_ratelimit())
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printk(KERN_WARNING
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"audit: audit_lost=%d audit_rate_limit=%d "
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"audit_backlog_limit=%d\n",
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atomic_read(&audit_lost),
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audit_rate_limit,
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audit_backlog_limit);
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audit_panic(message);
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}
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}
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static int audit_log_config_change(char *function_name, int new, int old,
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uid_t loginuid, u32 sessionid, u32 sid,
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int allow_changes)
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{
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struct audit_buffer *ab;
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int rc = 0;
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ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
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audit_log_format(ab, "%s=%d old=%d auid=%u ses=%u", function_name, new,
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old, loginuid, sessionid);
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if (sid) {
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char *ctx = NULL;
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u32 len;
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rc = security_secid_to_secctx(sid, &ctx, &len);
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if (rc) {
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audit_log_format(ab, " sid=%u", sid);
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allow_changes = 0; /* Something weird, deny request */
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} else {
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audit_log_format(ab, " subj=%s", ctx);
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security_release_secctx(ctx, len);
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}
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}
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audit_log_format(ab, " res=%d", allow_changes);
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audit_log_end(ab);
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return rc;
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}
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static int audit_do_config_change(char *function_name, int *to_change,
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int new, uid_t loginuid, u32 sessionid,
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u32 sid)
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{
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int allow_changes, rc = 0, old = *to_change;
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/* check if we are locked */
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if (audit_enabled == AUDIT_LOCKED)
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allow_changes = 0;
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else
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allow_changes = 1;
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if (audit_enabled != AUDIT_OFF) {
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rc = audit_log_config_change(function_name, new, old, loginuid,
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sessionid, sid, allow_changes);
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if (rc)
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allow_changes = 0;
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}
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/* If we are allowed, make the change */
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if (allow_changes == 1)
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*to_change = new;
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/* Not allowed, update reason */
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else if (rc == 0)
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rc = -EPERM;
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return rc;
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}
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static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sessionid,
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u32 sid)
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{
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return audit_do_config_change("audit_rate_limit", &audit_rate_limit,
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limit, loginuid, sessionid, sid);
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}
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static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sessionid,
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u32 sid)
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{
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return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit,
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limit, loginuid, sessionid, sid);
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}
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static int audit_set_enabled(int state, uid_t loginuid, u32 sessionid, u32 sid)
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{
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int rc;
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if (state < AUDIT_OFF || state > AUDIT_LOCKED)
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return -EINVAL;
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rc = audit_do_config_change("audit_enabled", &audit_enabled, state,
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loginuid, sessionid, sid);
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if (!rc)
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audit_ever_enabled |= !!state;
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return rc;
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}
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static int audit_set_failure(int state, uid_t loginuid, u32 sessionid, u32 sid)
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{
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if (state != AUDIT_FAIL_SILENT
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&& state != AUDIT_FAIL_PRINTK
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&& state != AUDIT_FAIL_PANIC)
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return -EINVAL;
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return audit_do_config_change("audit_failure", &audit_failure, state,
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loginuid, sessionid, sid);
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}
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/*
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* Queue skbs to be sent to auditd when/if it comes back. These skbs should
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* already have been sent via prink/syslog and so if these messages are dropped
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* it is not a huge concern since we already passed the audit_log_lost()
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* notification and stuff. This is just nice to get audit messages during
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* boot before auditd is running or messages generated while auditd is stopped.
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* This only holds messages is audit_default is set, aka booting with audit=1
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* or building your kernel that way.
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*/
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static void audit_hold_skb(struct sk_buff *skb)
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{
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if (audit_default &&
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skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit)
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skb_queue_tail(&audit_skb_hold_queue, skb);
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else
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kfree_skb(skb);
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}
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/*
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* For one reason or another this nlh isn't getting delivered to the userspace
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* audit daemon, just send it to printk.
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*/
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static void audit_printk_skb(struct sk_buff *skb)
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{
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struct nlmsghdr *nlh = nlmsg_hdr(skb);
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char *data = nlmsg_data(nlh);
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if (nlh->nlmsg_type != AUDIT_EOE) {
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if (printk_ratelimit())
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printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data);
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else
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audit_log_lost("printk limit exceeded\n");
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}
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audit_hold_skb(skb);
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}
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static void kauditd_send_skb(struct sk_buff *skb)
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{
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int err;
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/* take a reference in case we can't send it and we want to hold it */
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skb_get(skb);
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err = netlink_unicast(audit_sock, skb, audit_nlk_pid, 0);
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if (err < 0) {
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BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */
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printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid);
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audit_log_lost("auditd disappeared\n");
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audit_pid = 0;
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/* we might get lucky and get this in the next auditd */
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audit_hold_skb(skb);
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} else
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/* drop the extra reference if sent ok */
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consume_skb(skb);
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}
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static int kauditd_thread(void *dummy)
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{
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struct sk_buff *skb;
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set_freezable();
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while (!kthread_should_stop()) {
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/*
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* if auditd just started drain the queue of messages already
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* sent to syslog/printk. remember loss here is ok. we already
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* called audit_log_lost() if it didn't go out normally. so the
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* race between the skb_dequeue and the next check for audit_pid
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* doesn't matter.
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*
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* if you ever find kauditd to be too slow we can get a perf win
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* by doing our own locking and keeping better track if there
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* are messages in this queue. I don't see the need now, but
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* in 5 years when I want to play with this again I'll see this
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* note and still have no friggin idea what i'm thinking today.
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*/
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if (audit_default && audit_pid) {
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skb = skb_dequeue(&audit_skb_hold_queue);
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if (unlikely(skb)) {
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while (skb && audit_pid) {
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kauditd_send_skb(skb);
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skb = skb_dequeue(&audit_skb_hold_queue);
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}
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}
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}
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skb = skb_dequeue(&audit_skb_queue);
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wake_up(&audit_backlog_wait);
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if (skb) {
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if (audit_pid)
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kauditd_send_skb(skb);
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else
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audit_printk_skb(skb);
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} else {
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DECLARE_WAITQUEUE(wait, current);
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set_current_state(TASK_INTERRUPTIBLE);
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add_wait_queue(&kauditd_wait, &wait);
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|
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if (!skb_queue_len(&audit_skb_queue)) {
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try_to_freeze();
|
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schedule();
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}
|
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|
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__set_current_state(TASK_RUNNING);
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remove_wait_queue(&kauditd_wait, &wait);
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}
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}
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return 0;
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}
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|
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static int audit_prepare_user_tty(pid_t pid, uid_t loginuid, u32 sessionid)
|
|
{
|
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struct task_struct *tsk;
|
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int err;
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|
|
rcu_read_lock();
|
|
tsk = find_task_by_vpid(pid);
|
|
if (!tsk) {
|
|
rcu_read_unlock();
|
|
return -ESRCH;
|
|
}
|
|
get_task_struct(tsk);
|
|
rcu_read_unlock();
|
|
err = tty_audit_push_task(tsk, loginuid, sessionid);
|
|
put_task_struct(tsk);
|
|
return err;
|
|
}
|
|
|
|
int audit_send_list(void *_dest)
|
|
{
|
|
struct audit_netlink_list *dest = _dest;
|
|
int pid = dest->pid;
|
|
struct sk_buff *skb;
|
|
|
|
/* wait for parent to finish and send an ACK */
|
|
mutex_lock(&audit_cmd_mutex);
|
|
mutex_unlock(&audit_cmd_mutex);
|
|
|
|
while ((skb = __skb_dequeue(&dest->q)) != NULL)
|
|
netlink_unicast(audit_sock, skb, pid, 0);
|
|
|
|
kfree(dest);
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct sk_buff *audit_make_reply(int pid, int seq, int type, int done,
|
|
int multi, const void *payload, int size)
|
|
{
|
|
struct sk_buff *skb;
|
|
struct nlmsghdr *nlh;
|
|
void *data;
|
|
int flags = multi ? NLM_F_MULTI : 0;
|
|
int t = done ? NLMSG_DONE : type;
|
|
|
|
skb = nlmsg_new(size, GFP_KERNEL);
|
|
if (!skb)
|
|
return NULL;
|
|
|
|
nlh = nlmsg_put(skb, pid, seq, t, size, flags);
|
|
if (!nlh)
|
|
goto out_kfree_skb;
|
|
data = nlmsg_data(nlh);
|
|
memcpy(data, payload, size);
|
|
return skb;
|
|
|
|
out_kfree_skb:
|
|
kfree_skb(skb);
|
|
return NULL;
|
|
}
|
|
|
|
static int audit_send_reply_thread(void *arg)
|
|
{
|
|
struct audit_reply *reply = (struct audit_reply *)arg;
|
|
|
|
mutex_lock(&audit_cmd_mutex);
|
|
mutex_unlock(&audit_cmd_mutex);
|
|
|
|
/* Ignore failure. It'll only happen if the sender goes away,
|
|
because our timeout is set to infinite. */
|
|
netlink_unicast(audit_sock, reply->skb, reply->pid, 0);
|
|
kfree(reply);
|
|
return 0;
|
|
}
|
|
/**
|
|
* audit_send_reply - send an audit reply message via netlink
|
|
* @pid: process id to send reply to
|
|
* @seq: sequence number
|
|
* @type: audit message type
|
|
* @done: done (last) flag
|
|
* @multi: multi-part message flag
|
|
* @payload: payload data
|
|
* @size: payload size
|
|
*
|
|
* Allocates an skb, builds the netlink message, and sends it to the pid.
|
|
* No failure notifications.
|
|
*/
|
|
static void audit_send_reply(int pid, int seq, int type, int done, int multi,
|
|
const void *payload, int size)
|
|
{
|
|
struct sk_buff *skb;
|
|
struct task_struct *tsk;
|
|
struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
|
|
GFP_KERNEL);
|
|
|
|
if (!reply)
|
|
return;
|
|
|
|
skb = audit_make_reply(pid, seq, type, done, multi, payload, size);
|
|
if (!skb)
|
|
goto out;
|
|
|
|
reply->pid = pid;
|
|
reply->skb = skb;
|
|
|
|
tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
|
|
if (!IS_ERR(tsk))
|
|
return;
|
|
kfree_skb(skb);
|
|
out:
|
|
kfree(reply);
|
|
}
|
|
|
|
/*
|
|
* Check for appropriate CAP_AUDIT_ capabilities on incoming audit
|
|
* control messages.
|
|
*/
|
|
static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
|
|
{
|
|
int err = 0;
|
|
|
|
switch (msg_type) {
|
|
case AUDIT_GET:
|
|
case AUDIT_LIST:
|
|
case AUDIT_LIST_RULES:
|
|
case AUDIT_SET:
|
|
case AUDIT_ADD:
|
|
case AUDIT_ADD_RULE:
|
|
case AUDIT_DEL:
|
|
case AUDIT_DEL_RULE:
|
|
case AUDIT_SIGNAL_INFO:
|
|
case AUDIT_TTY_GET:
|
|
case AUDIT_TTY_SET:
|
|
case AUDIT_TRIM:
|
|
case AUDIT_MAKE_EQUIV:
|
|
if (!capable(CAP_AUDIT_CONTROL))
|
|
err = -EPERM;
|
|
break;
|
|
case AUDIT_USER:
|
|
case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
|
|
case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
|
|
if (!capable(CAP_AUDIT_WRITE))
|
|
err = -EPERM;
|
|
break;
|
|
default: /* bad msg */
|
|
err = -EINVAL;
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type,
|
|
u32 pid, u32 uid, uid_t auid, u32 ses,
|
|
u32 sid)
|
|
{
|
|
int rc = 0;
|
|
char *ctx = NULL;
|
|
u32 len;
|
|
|
|
if (!audit_enabled) {
|
|
*ab = NULL;
|
|
return rc;
|
|
}
|
|
|
|
*ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
|
|
audit_log_format(*ab, "pid=%d uid=%u auid=%u ses=%u",
|
|
pid, uid, auid, ses);
|
|
if (sid) {
|
|
rc = security_secid_to_secctx(sid, &ctx, &len);
|
|
if (rc)
|
|
audit_log_format(*ab, " ssid=%u", sid);
|
|
else {
|
|
audit_log_format(*ab, " subj=%s", ctx);
|
|
security_release_secctx(ctx, len);
|
|
}
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
|
|
{
|
|
u32 uid, pid, seq, sid;
|
|
void *data;
|
|
struct audit_status *status_get, status_set;
|
|
int err;
|
|
struct audit_buffer *ab;
|
|
u16 msg_type = nlh->nlmsg_type;
|
|
uid_t loginuid; /* loginuid of sender */
|
|
u32 sessionid;
|
|
struct audit_sig_info *sig_data;
|
|
char *ctx = NULL;
|
|
u32 len;
|
|
|
|
err = audit_netlink_ok(skb, msg_type);
|
|
if (err)
|
|
return err;
|
|
|
|
/* As soon as there's any sign of userspace auditd,
|
|
* start kauditd to talk to it */
|
|
if (!kauditd_task)
|
|
kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
|
|
if (IS_ERR(kauditd_task)) {
|
|
err = PTR_ERR(kauditd_task);
|
|
kauditd_task = NULL;
|
|
return err;
|
|
}
|
|
|
|
pid = NETLINK_CREDS(skb)->pid;
|
|
uid = NETLINK_CREDS(skb)->uid;
|
|
loginuid = audit_get_loginuid(current);
|
|
sessionid = audit_get_sessionid(current);
|
|
security_task_getsecid(current, &sid);
|
|
seq = nlh->nlmsg_seq;
|
|
data = nlmsg_data(nlh);
|
|
|
|
switch (msg_type) {
|
|
case AUDIT_GET:
|
|
status_set.enabled = audit_enabled;
|
|
status_set.failure = audit_failure;
|
|
status_set.pid = audit_pid;
|
|
status_set.rate_limit = audit_rate_limit;
|
|
status_set.backlog_limit = audit_backlog_limit;
|
|
status_set.lost = atomic_read(&audit_lost);
|
|
status_set.backlog = skb_queue_len(&audit_skb_queue);
|
|
audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_GET, 0, 0,
|
|
&status_set, sizeof(status_set));
|
|
break;
|
|
case AUDIT_SET:
|
|
if (nlh->nlmsg_len < sizeof(struct audit_status))
|
|
return -EINVAL;
|
|
status_get = (struct audit_status *)data;
|
|
if (status_get->mask & AUDIT_STATUS_ENABLED) {
|
|
err = audit_set_enabled(status_get->enabled,
|
|
loginuid, sessionid, sid);
|
|
if (err < 0)
|
|
return err;
|
|
}
|
|
if (status_get->mask & AUDIT_STATUS_FAILURE) {
|
|
err = audit_set_failure(status_get->failure,
|
|
loginuid, sessionid, sid);
|
|
if (err < 0)
|
|
return err;
|
|
}
|
|
if (status_get->mask & AUDIT_STATUS_PID) {
|
|
int new_pid = status_get->pid;
|
|
|
|
if (audit_enabled != AUDIT_OFF)
|
|
audit_log_config_change("audit_pid", new_pid,
|
|
audit_pid, loginuid,
|
|
sessionid, sid, 1);
|
|
|
|
audit_pid = new_pid;
|
|
audit_nlk_pid = NETLINK_CB(skb).pid;
|
|
}
|
|
if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) {
|
|
err = audit_set_rate_limit(status_get->rate_limit,
|
|
loginuid, sessionid, sid);
|
|
if (err < 0)
|
|
return err;
|
|
}
|
|
if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT)
|
|
err = audit_set_backlog_limit(status_get->backlog_limit,
|
|
loginuid, sessionid, sid);
|
|
break;
|
|
case AUDIT_USER:
|
|
case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
|
|
case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
|
|
if (!audit_enabled && msg_type != AUDIT_USER_AVC)
|
|
return 0;
|
|
|
|
err = audit_filter_user(&NETLINK_CB(skb));
|
|
if (err == 1) {
|
|
err = 0;
|
|
if (msg_type == AUDIT_USER_TTY) {
|
|
err = audit_prepare_user_tty(pid, loginuid,
|
|
sessionid);
|
|
if (err)
|
|
break;
|
|
}
|
|
audit_log_common_recv_msg(&ab, msg_type, pid, uid,
|
|
loginuid, sessionid, sid);
|
|
|
|
if (msg_type != AUDIT_USER_TTY)
|
|
audit_log_format(ab, " msg='%.1024s'",
|
|
(char *)data);
|
|
else {
|
|
int size;
|
|
|
|
audit_log_format(ab, " msg=");
|
|
size = nlmsg_len(nlh);
|
|
if (size > 0 &&
|
|
((unsigned char *)data)[size - 1] == '\0')
|
|
size--;
|
|
audit_log_n_untrustedstring(ab, data, size);
|
|
}
|
|
audit_set_pid(ab, pid);
|
|
audit_log_end(ab);
|
|
}
|
|
break;
|
|
case AUDIT_ADD:
|
|
case AUDIT_DEL:
|
|
if (nlmsg_len(nlh) < sizeof(struct audit_rule))
|
|
return -EINVAL;
|
|
if (audit_enabled == AUDIT_LOCKED) {
|
|
audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
|
|
uid, loginuid, sessionid, sid);
|
|
|
|
audit_log_format(ab, " audit_enabled=%d res=0",
|
|
audit_enabled);
|
|
audit_log_end(ab);
|
|
return -EPERM;
|
|
}
|
|
/* fallthrough */
|
|
case AUDIT_LIST:
|
|
err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid,
|
|
uid, seq, data, nlmsg_len(nlh),
|
|
loginuid, sessionid, sid);
|
|
break;
|
|
case AUDIT_ADD_RULE:
|
|
case AUDIT_DEL_RULE:
|
|
if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
|
|
return -EINVAL;
|
|
if (audit_enabled == AUDIT_LOCKED) {
|
|
audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
|
|
uid, loginuid, sessionid, sid);
|
|
|
|
audit_log_format(ab, " audit_enabled=%d res=0",
|
|
audit_enabled);
|
|
audit_log_end(ab);
|
|
return -EPERM;
|
|
}
|
|
/* fallthrough */
|
|
case AUDIT_LIST_RULES:
|
|
err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid,
|
|
uid, seq, data, nlmsg_len(nlh),
|
|
loginuid, sessionid, sid);
|
|
break;
|
|
case AUDIT_TRIM:
|
|
audit_trim_trees();
|
|
|
|
audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
|
|
uid, loginuid, sessionid, sid);
|
|
|
|
audit_log_format(ab, " op=trim res=1");
|
|
audit_log_end(ab);
|
|
break;
|
|
case AUDIT_MAKE_EQUIV: {
|
|
void *bufp = data;
|
|
u32 sizes[2];
|
|
size_t msglen = nlmsg_len(nlh);
|
|
char *old, *new;
|
|
|
|
err = -EINVAL;
|
|
if (msglen < 2 * sizeof(u32))
|
|
break;
|
|
memcpy(sizes, bufp, 2 * sizeof(u32));
|
|
bufp += 2 * sizeof(u32);
|
|
msglen -= 2 * sizeof(u32);
|
|
old = audit_unpack_string(&bufp, &msglen, sizes[0]);
|
|
if (IS_ERR(old)) {
|
|
err = PTR_ERR(old);
|
|
break;
|
|
}
|
|
new = audit_unpack_string(&bufp, &msglen, sizes[1]);
|
|
if (IS_ERR(new)) {
|
|
err = PTR_ERR(new);
|
|
kfree(old);
|
|
break;
|
|
}
|
|
/* OK, here comes... */
|
|
err = audit_tag_tree(old, new);
|
|
|
|
audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
|
|
uid, loginuid, sessionid, sid);
|
|
|
|
audit_log_format(ab, " op=make_equiv old=");
|
|
audit_log_untrustedstring(ab, old);
|
|
audit_log_format(ab, " new=");
|
|
audit_log_untrustedstring(ab, new);
|
|
audit_log_format(ab, " res=%d", !err);
|
|
audit_log_end(ab);
|
|
kfree(old);
|
|
kfree(new);
|
|
break;
|
|
}
|
|
case AUDIT_SIGNAL_INFO:
|
|
len = 0;
|
|
if (audit_sig_sid) {
|
|
err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
|
|
if (err)
|
|
return err;
|
|
}
|
|
sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
|
|
if (!sig_data) {
|
|
if (audit_sig_sid)
|
|
security_release_secctx(ctx, len);
|
|
return -ENOMEM;
|
|
}
|
|
sig_data->uid = audit_sig_uid;
|
|
sig_data->pid = audit_sig_pid;
|
|
if (audit_sig_sid) {
|
|
memcpy(sig_data->ctx, ctx, len);
|
|
security_release_secctx(ctx, len);
|
|
}
|
|
audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO,
|
|
0, 0, sig_data, sizeof(*sig_data) + len);
|
|
kfree(sig_data);
|
|
break;
|
|
case AUDIT_TTY_GET: {
|
|
struct audit_tty_status s;
|
|
struct task_struct *tsk;
|
|
unsigned long flags;
|
|
|
|
rcu_read_lock();
|
|
tsk = find_task_by_vpid(pid);
|
|
if (tsk && lock_task_sighand(tsk, &flags)) {
|
|
s.enabled = tsk->signal->audit_tty != 0;
|
|
unlock_task_sighand(tsk, &flags);
|
|
} else
|
|
err = -ESRCH;
|
|
rcu_read_unlock();
|
|
|
|
if (!err)
|
|
audit_send_reply(NETLINK_CB(skb).pid, seq,
|
|
AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
|
|
break;
|
|
}
|
|
case AUDIT_TTY_SET: {
|
|
struct audit_tty_status *s;
|
|
struct task_struct *tsk;
|
|
unsigned long flags;
|
|
|
|
if (nlh->nlmsg_len < sizeof(struct audit_tty_status))
|
|
return -EINVAL;
|
|
s = data;
|
|
if (s->enabled != 0 && s->enabled != 1)
|
|
return -EINVAL;
|
|
rcu_read_lock();
|
|
tsk = find_task_by_vpid(pid);
|
|
if (tsk && lock_task_sighand(tsk, &flags)) {
|
|
tsk->signal->audit_tty = s->enabled != 0;
|
|
unlock_task_sighand(tsk, &flags);
|
|
} else
|
|
err = -ESRCH;
|
|
rcu_read_unlock();
|
|
break;
|
|
}
|
|
default:
|
|
err = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
return err < 0 ? err : 0;
|
|
}
|
|
|
|
/*
|
|
* Get message from skb. Each message is processed by audit_receive_msg.
|
|
* Malformed skbs with wrong length are discarded silently.
|
|
*/
|
|
static void audit_receive_skb(struct sk_buff *skb)
|
|
{
|
|
struct nlmsghdr *nlh;
|
|
/*
|
|
* len MUST be signed for NLMSG_NEXT to be able to dec it below 0
|
|
* if the nlmsg_len was not aligned
|
|
*/
|
|
int len;
|
|
int err;
|
|
|
|
nlh = nlmsg_hdr(skb);
|
|
len = skb->len;
|
|
|
|
while (NLMSG_OK(nlh, len)) {
|
|
err = audit_receive_msg(skb, nlh);
|
|
/* if err or if this message says it wants a response */
|
|
if (err || (nlh->nlmsg_flags & NLM_F_ACK))
|
|
netlink_ack(skb, nlh, err);
|
|
|
|
nlh = NLMSG_NEXT(nlh, len);
|
|
}
|
|
}
|
|
|
|
/* Receive messages from netlink socket. */
|
|
static void audit_receive(struct sk_buff *skb)
|
|
{
|
|
mutex_lock(&audit_cmd_mutex);
|
|
audit_receive_skb(skb);
|
|
mutex_unlock(&audit_cmd_mutex);
|
|
}
|
|
|
|
/* Initialize audit support at boot time. */
|
|
static int __init audit_init(void)
|
|
{
|
|
int i;
|
|
struct netlink_kernel_cfg cfg = {
|
|
.input = audit_receive,
|
|
};
|
|
|
|
if (audit_initialized == AUDIT_DISABLED)
|
|
return 0;
|
|
|
|
printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
|
|
audit_default ? "enabled" : "disabled");
|
|
audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT,
|
|
THIS_MODULE, &cfg);
|
|
if (!audit_sock)
|
|
audit_panic("cannot initialize netlink socket");
|
|
else
|
|
audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
|
|
|
|
skb_queue_head_init(&audit_skb_queue);
|
|
skb_queue_head_init(&audit_skb_hold_queue);
|
|
audit_initialized = AUDIT_INITIALIZED;
|
|
audit_enabled = audit_default;
|
|
audit_ever_enabled |= !!audit_default;
|
|
|
|
audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
|
|
|
|
for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
|
|
INIT_LIST_HEAD(&audit_inode_hash[i]);
|
|
|
|
return 0;
|
|
}
|
|
__initcall(audit_init);
|
|
|
|
/* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
|
|
static int __init audit_enable(char *str)
|
|
{
|
|
audit_default = !!simple_strtol(str, NULL, 0);
|
|
if (!audit_default)
|
|
audit_initialized = AUDIT_DISABLED;
|
|
|
|
printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled");
|
|
|
|
if (audit_initialized == AUDIT_INITIALIZED) {
|
|
audit_enabled = audit_default;
|
|
audit_ever_enabled |= !!audit_default;
|
|
} else if (audit_initialized == AUDIT_UNINITIALIZED) {
|
|
printk(" (after initialization)");
|
|
} else {
|
|
printk(" (until reboot)");
|
|
}
|
|
printk("\n");
|
|
|
|
return 1;
|
|
}
|
|
|
|
__setup("audit=", audit_enable);
|
|
|
|
static void audit_buffer_free(struct audit_buffer *ab)
|
|
{
|
|
unsigned long flags;
|
|
|
|
if (!ab)
|
|
return;
|
|
|
|
if (ab->skb)
|
|
kfree_skb(ab->skb);
|
|
|
|
spin_lock_irqsave(&audit_freelist_lock, flags);
|
|
if (audit_freelist_count > AUDIT_MAXFREE)
|
|
kfree(ab);
|
|
else {
|
|
audit_freelist_count++;
|
|
list_add(&ab->list, &audit_freelist);
|
|
}
|
|
spin_unlock_irqrestore(&audit_freelist_lock, flags);
|
|
}
|
|
|
|
static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
|
|
gfp_t gfp_mask, int type)
|
|
{
|
|
unsigned long flags;
|
|
struct audit_buffer *ab = NULL;
|
|
struct nlmsghdr *nlh;
|
|
|
|
spin_lock_irqsave(&audit_freelist_lock, flags);
|
|
if (!list_empty(&audit_freelist)) {
|
|
ab = list_entry(audit_freelist.next,
|
|
struct audit_buffer, list);
|
|
list_del(&ab->list);
|
|
--audit_freelist_count;
|
|
}
|
|
spin_unlock_irqrestore(&audit_freelist_lock, flags);
|
|
|
|
if (!ab) {
|
|
ab = kmalloc(sizeof(*ab), gfp_mask);
|
|
if (!ab)
|
|
goto err;
|
|
}
|
|
|
|
ab->ctx = ctx;
|
|
ab->gfp_mask = gfp_mask;
|
|
|
|
ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
|
|
if (!ab->skb)
|
|
goto err;
|
|
|
|
nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0);
|
|
if (!nlh)
|
|
goto out_kfree_skb;
|
|
|
|
return ab;
|
|
|
|
out_kfree_skb:
|
|
kfree_skb(ab->skb);
|
|
ab->skb = NULL;
|
|
err:
|
|
audit_buffer_free(ab);
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* audit_serial - compute a serial number for the audit record
|
|
*
|
|
* Compute a serial number for the audit record. Audit records are
|
|
* written to user-space as soon as they are generated, so a complete
|
|
* audit record may be written in several pieces. The timestamp of the
|
|
* record and this serial number are used by the user-space tools to
|
|
* determine which pieces belong to the same audit record. The
|
|
* (timestamp,serial) tuple is unique for each syscall and is live from
|
|
* syscall entry to syscall exit.
|
|
*
|
|
* NOTE: Another possibility is to store the formatted records off the
|
|
* audit context (for those records that have a context), and emit them
|
|
* all at syscall exit. However, this could delay the reporting of
|
|
* significant errors until syscall exit (or never, if the system
|
|
* halts).
|
|
*/
|
|
unsigned int audit_serial(void)
|
|
{
|
|
static DEFINE_SPINLOCK(serial_lock);
|
|
static unsigned int serial = 0;
|
|
|
|
unsigned long flags;
|
|
unsigned int ret;
|
|
|
|
spin_lock_irqsave(&serial_lock, flags);
|
|
do {
|
|
ret = ++serial;
|
|
} while (unlikely(!ret));
|
|
spin_unlock_irqrestore(&serial_lock, flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static inline void audit_get_stamp(struct audit_context *ctx,
|
|
struct timespec *t, unsigned int *serial)
|
|
{
|
|
if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
|
|
*t = CURRENT_TIME;
|
|
*serial = audit_serial();
|
|
}
|
|
}
|
|
|
|
/* Obtain an audit buffer. This routine does locking to obtain the
|
|
* audit buffer, but then no locking is required for calls to
|
|
* audit_log_*format. If the tsk is a task that is currently in a
|
|
* syscall, then the syscall is marked as auditable and an audit record
|
|
* will be written at syscall exit. If there is no associated task, tsk
|
|
* should be NULL. */
|
|
|
|
/**
|
|
* audit_log_start - obtain an audit buffer
|
|
* @ctx: audit_context (may be NULL)
|
|
* @gfp_mask: type of allocation
|
|
* @type: audit message type
|
|
*
|
|
* Returns audit_buffer pointer on success or NULL on error.
|
|
*
|
|
* Obtain an audit buffer. This routine does locking to obtain the
|
|
* audit buffer, but then no locking is required for calls to
|
|
* audit_log_*format. If the task (ctx) is a task that is currently in a
|
|
* syscall, then the syscall is marked as auditable and an audit record
|
|
* will be written at syscall exit. If there is no associated task, then
|
|
* task context (ctx) should be NULL.
|
|
*/
|
|
struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
|
|
int type)
|
|
{
|
|
struct audit_buffer *ab = NULL;
|
|
struct timespec t;
|
|
unsigned int uninitialized_var(serial);
|
|
int reserve;
|
|
unsigned long timeout_start = jiffies;
|
|
|
|
if (audit_initialized != AUDIT_INITIALIZED)
|
|
return NULL;
|
|
|
|
if (unlikely(audit_filter_type(type)))
|
|
return NULL;
|
|
|
|
if (gfp_mask & __GFP_WAIT)
|
|
reserve = 0;
|
|
else
|
|
reserve = 5; /* Allow atomic callers to go up to five
|
|
entries over the normal backlog limit */
|
|
|
|
while (audit_backlog_limit
|
|
&& skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
|
|
if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time
|
|
&& time_before(jiffies, timeout_start + audit_backlog_wait_time)) {
|
|
|
|
/* Wait for auditd to drain the queue a little */
|
|
DECLARE_WAITQUEUE(wait, current);
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
add_wait_queue(&audit_backlog_wait, &wait);
|
|
|
|
if (audit_backlog_limit &&
|
|
skb_queue_len(&audit_skb_queue) > audit_backlog_limit)
|
|
schedule_timeout(timeout_start + audit_backlog_wait_time - jiffies);
|
|
|
|
__set_current_state(TASK_RUNNING);
|
|
remove_wait_queue(&audit_backlog_wait, &wait);
|
|
continue;
|
|
}
|
|
if (audit_rate_check() && printk_ratelimit())
|
|
printk(KERN_WARNING
|
|
"audit: audit_backlog=%d > "
|
|
"audit_backlog_limit=%d\n",
|
|
skb_queue_len(&audit_skb_queue),
|
|
audit_backlog_limit);
|
|
audit_log_lost("backlog limit exceeded");
|
|
audit_backlog_wait_time = audit_backlog_wait_overflow;
|
|
wake_up(&audit_backlog_wait);
|
|
return NULL;
|
|
}
|
|
|
|
ab = audit_buffer_alloc(ctx, gfp_mask, type);
|
|
if (!ab) {
|
|
audit_log_lost("out of memory in audit_log_start");
|
|
return NULL;
|
|
}
|
|
|
|
audit_get_stamp(ab->ctx, &t, &serial);
|
|
|
|
audit_log_format(ab, "audit(%lu.%03lu:%u): ",
|
|
t.tv_sec, t.tv_nsec/1000000, serial);
|
|
return ab;
|
|
}
|
|
|
|
/**
|
|
* audit_expand - expand skb in the audit buffer
|
|
* @ab: audit_buffer
|
|
* @extra: space to add at tail of the skb
|
|
*
|
|
* Returns 0 (no space) on failed expansion, or available space if
|
|
* successful.
|
|
*/
|
|
static inline int audit_expand(struct audit_buffer *ab, int extra)
|
|
{
|
|
struct sk_buff *skb = ab->skb;
|
|
int oldtail = skb_tailroom(skb);
|
|
int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
|
|
int newtail = skb_tailroom(skb);
|
|
|
|
if (ret < 0) {
|
|
audit_log_lost("out of memory in audit_expand");
|
|
return 0;
|
|
}
|
|
|
|
skb->truesize += newtail - oldtail;
|
|
return newtail;
|
|
}
|
|
|
|
/*
|
|
* Format an audit message into the audit buffer. If there isn't enough
|
|
* room in the audit buffer, more room will be allocated and vsnprint
|
|
* will be called a second time. Currently, we assume that a printk
|
|
* can't format message larger than 1024 bytes, so we don't either.
|
|
*/
|
|
static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
|
|
va_list args)
|
|
{
|
|
int len, avail;
|
|
struct sk_buff *skb;
|
|
va_list args2;
|
|
|
|
if (!ab)
|
|
return;
|
|
|
|
BUG_ON(!ab->skb);
|
|
skb = ab->skb;
|
|
avail = skb_tailroom(skb);
|
|
if (avail == 0) {
|
|
avail = audit_expand(ab, AUDIT_BUFSIZ);
|
|
if (!avail)
|
|
goto out;
|
|
}
|
|
va_copy(args2, args);
|
|
len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
|
|
if (len >= avail) {
|
|
/* The printk buffer is 1024 bytes long, so if we get
|
|
* here and AUDIT_BUFSIZ is at least 1024, then we can
|
|
* log everything that printk could have logged. */
|
|
avail = audit_expand(ab,
|
|
max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
|
|
if (!avail)
|
|
goto out_va_end;
|
|
len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
|
|
}
|
|
if (len > 0)
|
|
skb_put(skb, len);
|
|
out_va_end:
|
|
va_end(args2);
|
|
out:
|
|
return;
|
|
}
|
|
|
|
/**
|
|
* audit_log_format - format a message into the audit buffer.
|
|
* @ab: audit_buffer
|
|
* @fmt: format string
|
|
* @...: optional parameters matching @fmt string
|
|
*
|
|
* All the work is done in audit_log_vformat.
|
|
*/
|
|
void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
|
|
{
|
|
va_list args;
|
|
|
|
if (!ab)
|
|
return;
|
|
va_start(args, fmt);
|
|
audit_log_vformat(ab, fmt, args);
|
|
va_end(args);
|
|
}
|
|
|
|
/**
|
|
* audit_log_hex - convert a buffer to hex and append it to the audit skb
|
|
* @ab: the audit_buffer
|
|
* @buf: buffer to convert to hex
|
|
* @len: length of @buf to be converted
|
|
*
|
|
* No return value; failure to expand is silently ignored.
|
|
*
|
|
* This function will take the passed buf and convert it into a string of
|
|
* ascii hex digits. The new string is placed onto the skb.
|
|
*/
|
|
void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
|
|
size_t len)
|
|
{
|
|
int i, avail, new_len;
|
|
unsigned char *ptr;
|
|
struct sk_buff *skb;
|
|
static const unsigned char *hex = "0123456789ABCDEF";
|
|
|
|
if (!ab)
|
|
return;
|
|
|
|
BUG_ON(!ab->skb);
|
|
skb = ab->skb;
|
|
avail = skb_tailroom(skb);
|
|
new_len = len<<1;
|
|
if (new_len >= avail) {
|
|
/* Round the buffer request up to the next multiple */
|
|
new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
|
|
avail = audit_expand(ab, new_len);
|
|
if (!avail)
|
|
return;
|
|
}
|
|
|
|
ptr = skb_tail_pointer(skb);
|
|
for (i=0; i<len; i++) {
|
|
*ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */
|
|
*ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */
|
|
}
|
|
*ptr = 0;
|
|
skb_put(skb, len << 1); /* new string is twice the old string */
|
|
}
|
|
|
|
/*
|
|
* Format a string of no more than slen characters into the audit buffer,
|
|
* enclosed in quote marks.
|
|
*/
|
|
void audit_log_n_string(struct audit_buffer *ab, const char *string,
|
|
size_t slen)
|
|
{
|
|
int avail, new_len;
|
|
unsigned char *ptr;
|
|
struct sk_buff *skb;
|
|
|
|
if (!ab)
|
|
return;
|
|
|
|
BUG_ON(!ab->skb);
|
|
skb = ab->skb;
|
|
avail = skb_tailroom(skb);
|
|
new_len = slen + 3; /* enclosing quotes + null terminator */
|
|
if (new_len > avail) {
|
|
avail = audit_expand(ab, new_len);
|
|
if (!avail)
|
|
return;
|
|
}
|
|
ptr = skb_tail_pointer(skb);
|
|
*ptr++ = '"';
|
|
memcpy(ptr, string, slen);
|
|
ptr += slen;
|
|
*ptr++ = '"';
|
|
*ptr = 0;
|
|
skb_put(skb, slen + 2); /* don't include null terminator */
|
|
}
|
|
|
|
/**
|
|
* audit_string_contains_control - does a string need to be logged in hex
|
|
* @string: string to be checked
|
|
* @len: max length of the string to check
|
|
*/
|
|
int audit_string_contains_control(const char *string, size_t len)
|
|
{
|
|
const unsigned char *p;
|
|
for (p = string; p < (const unsigned char *)string + len; p++) {
|
|
if (*p == '"' || *p < 0x21 || *p > 0x7e)
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* audit_log_n_untrustedstring - log a string that may contain random characters
|
|
* @ab: audit_buffer
|
|
* @len: length of string (not including trailing null)
|
|
* @string: string to be logged
|
|
*
|
|
* This code will escape a string that is passed to it if the string
|
|
* contains a control character, unprintable character, double quote mark,
|
|
* or a space. Unescaped strings will start and end with a double quote mark.
|
|
* Strings that are escaped are printed in hex (2 digits per char).
|
|
*
|
|
* The caller specifies the number of characters in the string to log, which may
|
|
* or may not be the entire string.
|
|
*/
|
|
void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
|
|
size_t len)
|
|
{
|
|
if (audit_string_contains_control(string, len))
|
|
audit_log_n_hex(ab, string, len);
|
|
else
|
|
audit_log_n_string(ab, string, len);
|
|
}
|
|
|
|
/**
|
|
* audit_log_untrustedstring - log a string that may contain random characters
|
|
* @ab: audit_buffer
|
|
* @string: string to be logged
|
|
*
|
|
* Same as audit_log_n_untrustedstring(), except that strlen is used to
|
|
* determine string length.
|
|
*/
|
|
void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
|
|
{
|
|
audit_log_n_untrustedstring(ab, string, strlen(string));
|
|
}
|
|
|
|
/* This is a helper-function to print the escaped d_path */
|
|
void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
|
|
const struct path *path)
|
|
{
|
|
char *p, *pathname;
|
|
|
|
if (prefix)
|
|
audit_log_format(ab, "%s", prefix);
|
|
|
|
/* We will allow 11 spaces for ' (deleted)' to be appended */
|
|
pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
|
|
if (!pathname) {
|
|
audit_log_string(ab, "<no_memory>");
|
|
return;
|
|
}
|
|
p = d_path(path, pathname, PATH_MAX+11);
|
|
if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
|
|
/* FIXME: can we save some information here? */
|
|
audit_log_string(ab, "<too_long>");
|
|
} else
|
|
audit_log_untrustedstring(ab, p);
|
|
kfree(pathname);
|
|
}
|
|
|
|
void audit_log_key(struct audit_buffer *ab, char *key)
|
|
{
|
|
audit_log_format(ab, " key=");
|
|
if (key)
|
|
audit_log_untrustedstring(ab, key);
|
|
else
|
|
audit_log_format(ab, "(null)");
|
|
}
|
|
|
|
/**
|
|
* audit_log_link_denied - report a link restriction denial
|
|
* @operation: specific link opreation
|
|
* @link: the path that triggered the restriction
|
|
*/
|
|
void audit_log_link_denied(const char *operation, struct path *link)
|
|
{
|
|
struct audit_buffer *ab;
|
|
|
|
ab = audit_log_start(current->audit_context, GFP_KERNEL,
|
|
AUDIT_ANOM_LINK);
|
|
audit_log_format(ab, "op=%s action=denied", operation);
|
|
audit_log_format(ab, " pid=%d comm=", current->pid);
|
|
audit_log_untrustedstring(ab, current->comm);
|
|
audit_log_d_path(ab, " path=", link);
|
|
audit_log_format(ab, " dev=");
|
|
audit_log_untrustedstring(ab, link->dentry->d_inode->i_sb->s_id);
|
|
audit_log_format(ab, " ino=%lu", link->dentry->d_inode->i_ino);
|
|
audit_log_end(ab);
|
|
}
|
|
|
|
/**
|
|
* audit_log_end - end one audit record
|
|
* @ab: the audit_buffer
|
|
*
|
|
* The netlink_* functions cannot be called inside an irq context, so
|
|
* the audit buffer is placed on a queue and a tasklet is scheduled to
|
|
* remove them from the queue outside the irq context. May be called in
|
|
* any context.
|
|
*/
|
|
void audit_log_end(struct audit_buffer *ab)
|
|
{
|
|
if (!ab)
|
|
return;
|
|
if (!audit_rate_check()) {
|
|
audit_log_lost("rate limit exceeded");
|
|
} else {
|
|
struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
|
|
nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0);
|
|
|
|
if (audit_pid) {
|
|
skb_queue_tail(&audit_skb_queue, ab->skb);
|
|
wake_up_interruptible(&kauditd_wait);
|
|
} else {
|
|
audit_printk_skb(ab->skb);
|
|
}
|
|
ab->skb = NULL;
|
|
}
|
|
audit_buffer_free(ab);
|
|
}
|
|
|
|
/**
|
|
* audit_log - Log an audit record
|
|
* @ctx: audit context
|
|
* @gfp_mask: type of allocation
|
|
* @type: audit message type
|
|
* @fmt: format string to use
|
|
* @...: variable parameters matching the format string
|
|
*
|
|
* This is a convenience function that calls audit_log_start,
|
|
* audit_log_vformat, and audit_log_end. It may be called
|
|
* in any context.
|
|
*/
|
|
void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
|
|
const char *fmt, ...)
|
|
{
|
|
struct audit_buffer *ab;
|
|
va_list args;
|
|
|
|
ab = audit_log_start(ctx, gfp_mask, type);
|
|
if (ab) {
|
|
va_start(args, fmt);
|
|
audit_log_vformat(ab, fmt, args);
|
|
va_end(args);
|
|
audit_log_end(ab);
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_SECURITY
|
|
/**
|
|
* audit_log_secctx - Converts and logs SELinux context
|
|
* @ab: audit_buffer
|
|
* @secid: security number
|
|
*
|
|
* This is a helper function that calls security_secid_to_secctx to convert
|
|
* secid to secctx and then adds the (converted) SELinux context to the audit
|
|
* log by calling audit_log_format, thus also preventing leak of internal secid
|
|
* to userspace. If secid cannot be converted audit_panic is called.
|
|
*/
|
|
void audit_log_secctx(struct audit_buffer *ab, u32 secid)
|
|
{
|
|
u32 len;
|
|
char *secctx;
|
|
|
|
if (security_secid_to_secctx(secid, &secctx, &len)) {
|
|
audit_panic("Cannot convert secid to context");
|
|
} else {
|
|
audit_log_format(ab, " obj=%s", secctx);
|
|
security_release_secctx(secctx, len);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(audit_log_secctx);
|
|
#endif
|
|
|
|
EXPORT_SYMBOL(audit_log_start);
|
|
EXPORT_SYMBOL(audit_log_end);
|
|
EXPORT_SYMBOL(audit_log_format);
|
|
EXPORT_SYMBOL(audit_log);
|