xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

apparmor: fix aa_xattrs_match() may sleep while holding a RCU lock

Browse Source 
aa_xattrs_match() is unfortunately calling vfs_getxattr_alloc() from a
context protected by an rcu_read_lock. This can not be done as
vfs_getxattr_alloc() may sleep regardles of the gfp_t value being
passed to it.

Fix this by breaking the rcu_read_lock on the policy search when the
xattr match feature is requested and restarting the search if a policy
changes occur.

Fixes: 8e51f9087f ("apparmor: Add support for attaching profiles via xattr, presence and value")
Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: John Johansen <john.johansen@canonical.com>
This commit is contained in:
John Johansen
2020-01-02 05:31:22 -08:00
parent 20d4e80d25
commit 8c62ed27a1
3 changed files with 45 additions and 41 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
security/apparmor/policy.c
View File

@@ -1125,8 +1125,8 @@ ssize_t aa_remove_profiles(struct aa_ns *policy_ns, struct aa_label *subj,
if (!name) {
/* remove namespace - can only happen if fqname[0] == ':' */
mutex_lock_nested(&ns->parent->lock, ns->level);
__aa_remove_ns(ns);
__aa_bump_ns_revision(ns);
__aa_remove_ns(ns);
mutex_unlock(&ns->parent->lock);
} else {
/* remove profile */
@@ -1138,9 +1138,9 @@ ssize_t aa_remove_profiles(struct aa_ns *policy_ns, struct aa_label *subj,
goto fail_ns_lock;
}
name = profile->base.hname;
__aa_bump_ns_revision(ns);
__remove_profile(profile);
__aa_labelset_update_subtree(ns);
__aa_bump_ns_revision(ns);
mutex_unlock(&ns->lock);
}