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![Christoph Hellwig](/assets/img/avatar_default.png)
Various filesystems don't bother checking for a NULL ACL in posix_acl_equiv_mode, and thus can dereference a NULL pointer when it gets passed one. This usually happens from the NFS server, as the ACL tools never pass a NULL ACL, but instead of one representing the mode bits. Instead of adding boilerplat to all filesystems put this check into one place, which will allow us to remove the check from other filesystems as well later on. Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Ben Greear <greearb@candelatech.com> Reported-by: Marco Munderloh <munderl@tnt.uni-hannover.de>, Cc: Chuck Lever <chuck.lever@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
901 lines
20 KiB
C
901 lines
20 KiB
C
/*
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* Copyright (C) 2002,2003 by Andreas Gruenbacher <a.gruenbacher@computer.org>
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*
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* Fixes from William Schumacher incorporated on 15 March 2001.
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* (Reported by Charles Bertsch, <CBertsch@microtest.com>).
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*/
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/*
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* This file contains generic functions for manipulating
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* POSIX 1003.1e draft standard 17 ACLs.
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*/
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/atomic.h>
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#include <linux/fs.h>
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#include <linux/sched.h>
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#include <linux/posix_acl.h>
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#include <linux/posix_acl_xattr.h>
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#include <linux/xattr.h>
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#include <linux/export.h>
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#include <linux/user_namespace.h>
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struct posix_acl **acl_by_type(struct inode *inode, int type)
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{
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switch (type) {
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case ACL_TYPE_ACCESS:
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return &inode->i_acl;
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case ACL_TYPE_DEFAULT:
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return &inode->i_default_acl;
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default:
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BUG();
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}
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}
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EXPORT_SYMBOL(acl_by_type);
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struct posix_acl *get_cached_acl(struct inode *inode, int type)
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{
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struct posix_acl **p = acl_by_type(inode, type);
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struct posix_acl *acl = ACCESS_ONCE(*p);
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if (acl) {
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spin_lock(&inode->i_lock);
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acl = *p;
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if (acl != ACL_NOT_CACHED)
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acl = posix_acl_dup(acl);
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spin_unlock(&inode->i_lock);
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}
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return acl;
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}
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EXPORT_SYMBOL(get_cached_acl);
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struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type)
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{
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return rcu_dereference(*acl_by_type(inode, type));
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}
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EXPORT_SYMBOL(get_cached_acl_rcu);
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void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl)
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{
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struct posix_acl **p = acl_by_type(inode, type);
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struct posix_acl *old;
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spin_lock(&inode->i_lock);
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old = *p;
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rcu_assign_pointer(*p, posix_acl_dup(acl));
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spin_unlock(&inode->i_lock);
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if (old != ACL_NOT_CACHED)
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posix_acl_release(old);
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}
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EXPORT_SYMBOL(set_cached_acl);
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void forget_cached_acl(struct inode *inode, int type)
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{
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struct posix_acl **p = acl_by_type(inode, type);
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struct posix_acl *old;
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spin_lock(&inode->i_lock);
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old = *p;
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*p = ACL_NOT_CACHED;
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spin_unlock(&inode->i_lock);
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if (old != ACL_NOT_CACHED)
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posix_acl_release(old);
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}
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EXPORT_SYMBOL(forget_cached_acl);
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void forget_all_cached_acls(struct inode *inode)
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{
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struct posix_acl *old_access, *old_default;
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spin_lock(&inode->i_lock);
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old_access = inode->i_acl;
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old_default = inode->i_default_acl;
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inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED;
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spin_unlock(&inode->i_lock);
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if (old_access != ACL_NOT_CACHED)
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posix_acl_release(old_access);
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if (old_default != ACL_NOT_CACHED)
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posix_acl_release(old_default);
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}
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EXPORT_SYMBOL(forget_all_cached_acls);
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struct posix_acl *get_acl(struct inode *inode, int type)
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{
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struct posix_acl *acl;
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acl = get_cached_acl(inode, type);
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if (acl != ACL_NOT_CACHED)
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return acl;
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if (!IS_POSIXACL(inode))
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return NULL;
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/*
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* A filesystem can force a ACL callback by just never filling the
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* ACL cache. But normally you'd fill the cache either at inode
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* instantiation time, or on the first ->get_acl call.
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*
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* If the filesystem doesn't have a get_acl() function at all, we'll
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* just create the negative cache entry.
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*/
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if (!inode->i_op->get_acl) {
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set_cached_acl(inode, type, NULL);
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return NULL;
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}
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return inode->i_op->get_acl(inode, type);
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}
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EXPORT_SYMBOL(get_acl);
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/*
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* Init a fresh posix_acl
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*/
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void
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posix_acl_init(struct posix_acl *acl, int count)
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{
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atomic_set(&acl->a_refcount, 1);
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acl->a_count = count;
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}
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EXPORT_SYMBOL(posix_acl_init);
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/*
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* Allocate a new ACL with the specified number of entries.
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*/
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struct posix_acl *
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posix_acl_alloc(int count, gfp_t flags)
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{
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const size_t size = sizeof(struct posix_acl) +
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count * sizeof(struct posix_acl_entry);
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struct posix_acl *acl = kmalloc(size, flags);
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if (acl)
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posix_acl_init(acl, count);
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return acl;
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}
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EXPORT_SYMBOL(posix_acl_alloc);
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/*
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* Clone an ACL.
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*/
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static struct posix_acl *
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posix_acl_clone(const struct posix_acl *acl, gfp_t flags)
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{
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struct posix_acl *clone = NULL;
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if (acl) {
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int size = sizeof(struct posix_acl) + acl->a_count *
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sizeof(struct posix_acl_entry);
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clone = kmemdup(acl, size, flags);
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if (clone)
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atomic_set(&clone->a_refcount, 1);
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}
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return clone;
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}
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/*
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* Check if an acl is valid. Returns 0 if it is, or -E... otherwise.
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*/
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int
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posix_acl_valid(const struct posix_acl *acl)
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{
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const struct posix_acl_entry *pa, *pe;
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int state = ACL_USER_OBJ;
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int needs_mask = 0;
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FOREACH_ACL_ENTRY(pa, acl, pe) {
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if (pa->e_perm & ~(ACL_READ|ACL_WRITE|ACL_EXECUTE))
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return -EINVAL;
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switch (pa->e_tag) {
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case ACL_USER_OBJ:
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if (state == ACL_USER_OBJ) {
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state = ACL_USER;
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break;
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}
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return -EINVAL;
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case ACL_USER:
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if (state != ACL_USER)
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return -EINVAL;
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if (!uid_valid(pa->e_uid))
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return -EINVAL;
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needs_mask = 1;
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break;
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case ACL_GROUP_OBJ:
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if (state == ACL_USER) {
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state = ACL_GROUP;
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break;
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}
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return -EINVAL;
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case ACL_GROUP:
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if (state != ACL_GROUP)
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return -EINVAL;
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if (!gid_valid(pa->e_gid))
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return -EINVAL;
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needs_mask = 1;
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break;
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case ACL_MASK:
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if (state != ACL_GROUP)
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return -EINVAL;
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state = ACL_OTHER;
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break;
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case ACL_OTHER:
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if (state == ACL_OTHER ||
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(state == ACL_GROUP && !needs_mask)) {
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state = 0;
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break;
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}
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return -EINVAL;
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default:
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return -EINVAL;
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}
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}
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if (state == 0)
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return 0;
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return -EINVAL;
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}
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EXPORT_SYMBOL(posix_acl_valid);
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/*
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* Returns 0 if the acl can be exactly represented in the traditional
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* file mode permission bits, or else 1. Returns -E... on error.
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*/
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int
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posix_acl_equiv_mode(const struct posix_acl *acl, umode_t *mode_p)
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{
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const struct posix_acl_entry *pa, *pe;
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umode_t mode = 0;
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int not_equiv = 0;
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/*
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* A null ACL can always be presented as mode bits.
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*/
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if (!acl)
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return 0;
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FOREACH_ACL_ENTRY(pa, acl, pe) {
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switch (pa->e_tag) {
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case ACL_USER_OBJ:
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mode |= (pa->e_perm & S_IRWXO) << 6;
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break;
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case ACL_GROUP_OBJ:
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mode |= (pa->e_perm & S_IRWXO) << 3;
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break;
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case ACL_OTHER:
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mode |= pa->e_perm & S_IRWXO;
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break;
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case ACL_MASK:
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mode = (mode & ~S_IRWXG) |
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((pa->e_perm & S_IRWXO) << 3);
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not_equiv = 1;
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break;
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case ACL_USER:
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case ACL_GROUP:
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not_equiv = 1;
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break;
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default:
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return -EINVAL;
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}
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}
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if (mode_p)
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*mode_p = (*mode_p & ~S_IRWXUGO) | mode;
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return not_equiv;
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}
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EXPORT_SYMBOL(posix_acl_equiv_mode);
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/*
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* Create an ACL representing the file mode permission bits of an inode.
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*/
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struct posix_acl *
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posix_acl_from_mode(umode_t mode, gfp_t flags)
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{
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struct posix_acl *acl = posix_acl_alloc(3, flags);
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if (!acl)
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return ERR_PTR(-ENOMEM);
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acl->a_entries[0].e_tag = ACL_USER_OBJ;
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acl->a_entries[0].e_perm = (mode & S_IRWXU) >> 6;
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acl->a_entries[1].e_tag = ACL_GROUP_OBJ;
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acl->a_entries[1].e_perm = (mode & S_IRWXG) >> 3;
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acl->a_entries[2].e_tag = ACL_OTHER;
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acl->a_entries[2].e_perm = (mode & S_IRWXO);
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return acl;
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}
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EXPORT_SYMBOL(posix_acl_from_mode);
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/*
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* Return 0 if current is granted want access to the inode
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* by the acl. Returns -E... otherwise.
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*/
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int
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posix_acl_permission(struct inode *inode, const struct posix_acl *acl, int want)
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{
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const struct posix_acl_entry *pa, *pe, *mask_obj;
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int found = 0;
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want &= MAY_READ | MAY_WRITE | MAY_EXEC | MAY_NOT_BLOCK;
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FOREACH_ACL_ENTRY(pa, acl, pe) {
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switch(pa->e_tag) {
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case ACL_USER_OBJ:
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/* (May have been checked already) */
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if (uid_eq(inode->i_uid, current_fsuid()))
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goto check_perm;
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break;
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case ACL_USER:
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if (uid_eq(pa->e_uid, current_fsuid()))
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goto mask;
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break;
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case ACL_GROUP_OBJ:
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if (in_group_p(inode->i_gid)) {
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found = 1;
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if ((pa->e_perm & want) == want)
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goto mask;
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}
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break;
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case ACL_GROUP:
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if (in_group_p(pa->e_gid)) {
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found = 1;
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if ((pa->e_perm & want) == want)
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goto mask;
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}
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break;
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case ACL_MASK:
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break;
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case ACL_OTHER:
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if (found)
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return -EACCES;
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else
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goto check_perm;
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default:
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return -EIO;
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}
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}
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return -EIO;
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mask:
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for (mask_obj = pa+1; mask_obj != pe; mask_obj++) {
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if (mask_obj->e_tag == ACL_MASK) {
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if ((pa->e_perm & mask_obj->e_perm & want) == want)
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return 0;
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return -EACCES;
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}
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}
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check_perm:
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if ((pa->e_perm & want) == want)
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return 0;
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return -EACCES;
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}
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/*
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* Modify acl when creating a new inode. The caller must ensure the acl is
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* only referenced once.
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*
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* mode_p initially must contain the mode parameter to the open() / creat()
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* system calls. All permissions that are not granted by the acl are removed.
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* The permissions in the acl are changed to reflect the mode_p parameter.
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*/
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static int posix_acl_create_masq(struct posix_acl *acl, umode_t *mode_p)
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{
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struct posix_acl_entry *pa, *pe;
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struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
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umode_t mode = *mode_p;
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int not_equiv = 0;
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/* assert(atomic_read(acl->a_refcount) == 1); */
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FOREACH_ACL_ENTRY(pa, acl, pe) {
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switch(pa->e_tag) {
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case ACL_USER_OBJ:
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pa->e_perm &= (mode >> 6) | ~S_IRWXO;
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mode &= (pa->e_perm << 6) | ~S_IRWXU;
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break;
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case ACL_USER:
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case ACL_GROUP:
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not_equiv = 1;
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break;
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case ACL_GROUP_OBJ:
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group_obj = pa;
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break;
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case ACL_OTHER:
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pa->e_perm &= mode | ~S_IRWXO;
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mode &= pa->e_perm | ~S_IRWXO;
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break;
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case ACL_MASK:
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mask_obj = pa;
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not_equiv = 1;
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break;
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default:
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return -EIO;
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}
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}
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if (mask_obj) {
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mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
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mode &= (mask_obj->e_perm << 3) | ~S_IRWXG;
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} else {
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if (!group_obj)
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return -EIO;
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group_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
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mode &= (group_obj->e_perm << 3) | ~S_IRWXG;
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}
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*mode_p = (*mode_p & ~S_IRWXUGO) | mode;
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return not_equiv;
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}
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/*
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* Modify the ACL for the chmod syscall.
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*/
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static int __posix_acl_chmod_masq(struct posix_acl *acl, umode_t mode)
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{
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struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
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struct posix_acl_entry *pa, *pe;
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/* assert(atomic_read(acl->a_refcount) == 1); */
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FOREACH_ACL_ENTRY(pa, acl, pe) {
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switch(pa->e_tag) {
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case ACL_USER_OBJ:
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pa->e_perm = (mode & S_IRWXU) >> 6;
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break;
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case ACL_USER:
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case ACL_GROUP:
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break;
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case ACL_GROUP_OBJ:
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group_obj = pa;
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break;
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case ACL_MASK:
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mask_obj = pa;
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break;
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case ACL_OTHER:
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pa->e_perm = (mode & S_IRWXO);
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break;
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default:
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return -EIO;
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}
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}
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if (mask_obj) {
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mask_obj->e_perm = (mode & S_IRWXG) >> 3;
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} else {
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if (!group_obj)
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return -EIO;
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group_obj->e_perm = (mode & S_IRWXG) >> 3;
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}
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return 0;
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}
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int
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__posix_acl_create(struct posix_acl **acl, gfp_t gfp, umode_t *mode_p)
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{
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struct posix_acl *clone = posix_acl_clone(*acl, gfp);
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int err = -ENOMEM;
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if (clone) {
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err = posix_acl_create_masq(clone, mode_p);
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if (err < 0) {
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posix_acl_release(clone);
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clone = NULL;
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}
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}
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posix_acl_release(*acl);
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*acl = clone;
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return err;
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}
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EXPORT_SYMBOL(__posix_acl_create);
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int
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__posix_acl_chmod(struct posix_acl **acl, gfp_t gfp, umode_t mode)
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{
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struct posix_acl *clone = posix_acl_clone(*acl, gfp);
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int err = -ENOMEM;
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if (clone) {
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err = __posix_acl_chmod_masq(clone, mode);
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if (err) {
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posix_acl_release(clone);
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clone = NULL;
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}
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}
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posix_acl_release(*acl);
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*acl = clone;
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return err;
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}
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EXPORT_SYMBOL(__posix_acl_chmod);
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int
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posix_acl_chmod(struct inode *inode, umode_t mode)
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{
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struct posix_acl *acl;
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int ret = 0;
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if (!IS_POSIXACL(inode))
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return 0;
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if (!inode->i_op->set_acl)
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return -EOPNOTSUPP;
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|
|
acl = get_acl(inode, ACL_TYPE_ACCESS);
|
|
if (IS_ERR_OR_NULL(acl)) {
|
|
if (acl == ERR_PTR(-EOPNOTSUPP))
|
|
return 0;
|
|
return PTR_ERR(acl);
|
|
}
|
|
|
|
ret = __posix_acl_chmod(&acl, GFP_KERNEL, mode);
|
|
if (ret)
|
|
return ret;
|
|
ret = inode->i_op->set_acl(inode, acl, ACL_TYPE_ACCESS);
|
|
posix_acl_release(acl);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(posix_acl_chmod);
|
|
|
|
int
|
|
posix_acl_create(struct inode *dir, umode_t *mode,
|
|
struct posix_acl **default_acl, struct posix_acl **acl)
|
|
{
|
|
struct posix_acl *p;
|
|
int ret;
|
|
|
|
if (S_ISLNK(*mode) || !IS_POSIXACL(dir))
|
|
goto no_acl;
|
|
|
|
p = get_acl(dir, ACL_TYPE_DEFAULT);
|
|
if (IS_ERR(p)) {
|
|
if (p == ERR_PTR(-EOPNOTSUPP))
|
|
goto apply_umask;
|
|
return PTR_ERR(p);
|
|
}
|
|
|
|
if (!p)
|
|
goto apply_umask;
|
|
|
|
*acl = posix_acl_clone(p, GFP_NOFS);
|
|
if (!*acl)
|
|
return -ENOMEM;
|
|
|
|
ret = posix_acl_create_masq(*acl, mode);
|
|
if (ret < 0) {
|
|
posix_acl_release(*acl);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
if (ret == 0) {
|
|
posix_acl_release(*acl);
|
|
*acl = NULL;
|
|
}
|
|
|
|
if (!S_ISDIR(*mode)) {
|
|
posix_acl_release(p);
|
|
*default_acl = NULL;
|
|
} else {
|
|
*default_acl = p;
|
|
}
|
|
return 0;
|
|
|
|
apply_umask:
|
|
*mode &= ~current_umask();
|
|
no_acl:
|
|
*default_acl = NULL;
|
|
*acl = NULL;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(posix_acl_create);
|
|
|
|
/*
|
|
* Fix up the uids and gids in posix acl extended attributes in place.
|
|
*/
|
|
static void posix_acl_fix_xattr_userns(
|
|
struct user_namespace *to, struct user_namespace *from,
|
|
void *value, size_t size)
|
|
{
|
|
posix_acl_xattr_header *header = (posix_acl_xattr_header *)value;
|
|
posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end;
|
|
int count;
|
|
kuid_t uid;
|
|
kgid_t gid;
|
|
|
|
if (!value)
|
|
return;
|
|
if (size < sizeof(posix_acl_xattr_header))
|
|
return;
|
|
if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
|
|
return;
|
|
|
|
count = posix_acl_xattr_count(size);
|
|
if (count < 0)
|
|
return;
|
|
if (count == 0)
|
|
return;
|
|
|
|
for (end = entry + count; entry != end; entry++) {
|
|
switch(le16_to_cpu(entry->e_tag)) {
|
|
case ACL_USER:
|
|
uid = make_kuid(from, le32_to_cpu(entry->e_id));
|
|
entry->e_id = cpu_to_le32(from_kuid(to, uid));
|
|
break;
|
|
case ACL_GROUP:
|
|
gid = make_kgid(from, le32_to_cpu(entry->e_id));
|
|
entry->e_id = cpu_to_le32(from_kgid(to, gid));
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
void posix_acl_fix_xattr_from_user(void *value, size_t size)
|
|
{
|
|
struct user_namespace *user_ns = current_user_ns();
|
|
if (user_ns == &init_user_ns)
|
|
return;
|
|
posix_acl_fix_xattr_userns(&init_user_ns, user_ns, value, size);
|
|
}
|
|
|
|
void posix_acl_fix_xattr_to_user(void *value, size_t size)
|
|
{
|
|
struct user_namespace *user_ns = current_user_ns();
|
|
if (user_ns == &init_user_ns)
|
|
return;
|
|
posix_acl_fix_xattr_userns(user_ns, &init_user_ns, value, size);
|
|
}
|
|
|
|
/*
|
|
* Convert from extended attribute to in-memory representation.
|
|
*/
|
|
struct posix_acl *
|
|
posix_acl_from_xattr(struct user_namespace *user_ns,
|
|
const void *value, size_t size)
|
|
{
|
|
posix_acl_xattr_header *header = (posix_acl_xattr_header *)value;
|
|
posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end;
|
|
int count;
|
|
struct posix_acl *acl;
|
|
struct posix_acl_entry *acl_e;
|
|
|
|
if (!value)
|
|
return NULL;
|
|
if (size < sizeof(posix_acl_xattr_header))
|
|
return ERR_PTR(-EINVAL);
|
|
if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
|
|
return ERR_PTR(-EOPNOTSUPP);
|
|
|
|
count = posix_acl_xattr_count(size);
|
|
if (count < 0)
|
|
return ERR_PTR(-EINVAL);
|
|
if (count == 0)
|
|
return NULL;
|
|
|
|
acl = posix_acl_alloc(count, GFP_NOFS);
|
|
if (!acl)
|
|
return ERR_PTR(-ENOMEM);
|
|
acl_e = acl->a_entries;
|
|
|
|
for (end = entry + count; entry != end; acl_e++, entry++) {
|
|
acl_e->e_tag = le16_to_cpu(entry->e_tag);
|
|
acl_e->e_perm = le16_to_cpu(entry->e_perm);
|
|
|
|
switch(acl_e->e_tag) {
|
|
case ACL_USER_OBJ:
|
|
case ACL_GROUP_OBJ:
|
|
case ACL_MASK:
|
|
case ACL_OTHER:
|
|
break;
|
|
|
|
case ACL_USER:
|
|
acl_e->e_uid =
|
|
make_kuid(user_ns,
|
|
le32_to_cpu(entry->e_id));
|
|
if (!uid_valid(acl_e->e_uid))
|
|
goto fail;
|
|
break;
|
|
case ACL_GROUP:
|
|
acl_e->e_gid =
|
|
make_kgid(user_ns,
|
|
le32_to_cpu(entry->e_id));
|
|
if (!gid_valid(acl_e->e_gid))
|
|
goto fail;
|
|
break;
|
|
|
|
default:
|
|
goto fail;
|
|
}
|
|
}
|
|
return acl;
|
|
|
|
fail:
|
|
posix_acl_release(acl);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
EXPORT_SYMBOL (posix_acl_from_xattr);
|
|
|
|
/*
|
|
* Convert from in-memory to extended attribute representation.
|
|
*/
|
|
int
|
|
posix_acl_to_xattr(struct user_namespace *user_ns, const struct posix_acl *acl,
|
|
void *buffer, size_t size)
|
|
{
|
|
posix_acl_xattr_header *ext_acl = (posix_acl_xattr_header *)buffer;
|
|
posix_acl_xattr_entry *ext_entry;
|
|
int real_size, n;
|
|
|
|
real_size = posix_acl_xattr_size(acl->a_count);
|
|
if (!buffer)
|
|
return real_size;
|
|
if (real_size > size)
|
|
return -ERANGE;
|
|
|
|
ext_entry = ext_acl->a_entries;
|
|
ext_acl->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION);
|
|
|
|
for (n=0; n < acl->a_count; n++, ext_entry++) {
|
|
const struct posix_acl_entry *acl_e = &acl->a_entries[n];
|
|
ext_entry->e_tag = cpu_to_le16(acl_e->e_tag);
|
|
ext_entry->e_perm = cpu_to_le16(acl_e->e_perm);
|
|
switch(acl_e->e_tag) {
|
|
case ACL_USER:
|
|
ext_entry->e_id =
|
|
cpu_to_le32(from_kuid(user_ns, acl_e->e_uid));
|
|
break;
|
|
case ACL_GROUP:
|
|
ext_entry->e_id =
|
|
cpu_to_le32(from_kgid(user_ns, acl_e->e_gid));
|
|
break;
|
|
default:
|
|
ext_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
|
|
break;
|
|
}
|
|
}
|
|
return real_size;
|
|
}
|
|
EXPORT_SYMBOL (posix_acl_to_xattr);
|
|
|
|
static int
|
|
posix_acl_xattr_get(struct dentry *dentry, const char *name,
|
|
void *value, size_t size, int type)
|
|
{
|
|
struct posix_acl *acl;
|
|
int error;
|
|
|
|
if (!IS_POSIXACL(dentry->d_inode))
|
|
return -EOPNOTSUPP;
|
|
if (S_ISLNK(dentry->d_inode->i_mode))
|
|
return -EOPNOTSUPP;
|
|
|
|
acl = get_acl(dentry->d_inode, type);
|
|
if (IS_ERR(acl))
|
|
return PTR_ERR(acl);
|
|
if (acl == NULL)
|
|
return -ENODATA;
|
|
|
|
error = posix_acl_to_xattr(&init_user_ns, acl, value, size);
|
|
posix_acl_release(acl);
|
|
|
|
return error;
|
|
}
|
|
|
|
static int
|
|
posix_acl_xattr_set(struct dentry *dentry, const char *name,
|
|
const void *value, size_t size, int flags, int type)
|
|
{
|
|
struct inode *inode = dentry->d_inode;
|
|
struct posix_acl *acl = NULL;
|
|
int ret;
|
|
|
|
if (!IS_POSIXACL(inode))
|
|
return -EOPNOTSUPP;
|
|
if (!inode->i_op->set_acl)
|
|
return -EOPNOTSUPP;
|
|
|
|
if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
|
|
return value ? -EACCES : 0;
|
|
if (!inode_owner_or_capable(inode))
|
|
return -EPERM;
|
|
|
|
if (value) {
|
|
acl = posix_acl_from_xattr(&init_user_ns, value, size);
|
|
if (IS_ERR(acl))
|
|
return PTR_ERR(acl);
|
|
|
|
if (acl) {
|
|
ret = posix_acl_valid(acl);
|
|
if (ret)
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
ret = inode->i_op->set_acl(inode, acl, type);
|
|
out:
|
|
posix_acl_release(acl);
|
|
return ret;
|
|
}
|
|
|
|
static size_t
|
|
posix_acl_xattr_list(struct dentry *dentry, char *list, size_t list_size,
|
|
const char *name, size_t name_len, int type)
|
|
{
|
|
const char *xname;
|
|
size_t size;
|
|
|
|
if (!IS_POSIXACL(dentry->d_inode))
|
|
return -EOPNOTSUPP;
|
|
if (S_ISLNK(dentry->d_inode->i_mode))
|
|
return -EOPNOTSUPP;
|
|
|
|
if (type == ACL_TYPE_ACCESS)
|
|
xname = POSIX_ACL_XATTR_ACCESS;
|
|
else
|
|
xname = POSIX_ACL_XATTR_DEFAULT;
|
|
|
|
size = strlen(xname) + 1;
|
|
if (list && size <= list_size)
|
|
memcpy(list, xname, size);
|
|
return size;
|
|
}
|
|
|
|
const struct xattr_handler posix_acl_access_xattr_handler = {
|
|
.prefix = POSIX_ACL_XATTR_ACCESS,
|
|
.flags = ACL_TYPE_ACCESS,
|
|
.list = posix_acl_xattr_list,
|
|
.get = posix_acl_xattr_get,
|
|
.set = posix_acl_xattr_set,
|
|
};
|
|
EXPORT_SYMBOL_GPL(posix_acl_access_xattr_handler);
|
|
|
|
const struct xattr_handler posix_acl_default_xattr_handler = {
|
|
.prefix = POSIX_ACL_XATTR_DEFAULT,
|
|
.flags = ACL_TYPE_DEFAULT,
|
|
.list = posix_acl_xattr_list,
|
|
.get = posix_acl_xattr_get,
|
|
.set = posix_acl_xattr_set,
|
|
};
|
|
EXPORT_SYMBOL_GPL(posix_acl_default_xattr_handler);
|
|
|
|
int simple_set_acl(struct inode *inode, struct posix_acl *acl, int type)
|
|
{
|
|
int error;
|
|
|
|
if (type == ACL_TYPE_ACCESS) {
|
|
error = posix_acl_equiv_mode(acl, &inode->i_mode);
|
|
if (error < 0)
|
|
return 0;
|
|
if (error == 0)
|
|
acl = NULL;
|
|
}
|
|
|
|
inode->i_ctime = CURRENT_TIME;
|
|
set_cached_acl(inode, type, acl);
|
|
return 0;
|
|
}
|
|
|
|
int simple_acl_create(struct inode *dir, struct inode *inode)
|
|
{
|
|
struct posix_acl *default_acl, *acl;
|
|
int error;
|
|
|
|
error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
|
|
if (error)
|
|
return error;
|
|
|
|
set_cached_acl(inode, ACL_TYPE_DEFAULT, default_acl);
|
|
set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
|
|
|
|
if (default_acl)
|
|
posix_acl_release(default_acl);
|
|
if (acl)
|
|
posix_acl_release(acl);
|
|
return 0;
|
|
}
|