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author | Waiman Long <Waiman.Long@hp.com> | 2014-06-23 17:28:51 +0200 |
---|---|---|
committer | Paul Moore <pmoore@redhat.com> | 2014-06-23 22:52:55 +0200 |
commit | f31e799459659ae88c341aeac16a8a5efb1271d4 (patch) | |
tree | 912cc7f6dd3350c32501a344cf438f7ec2269c72 /security/selinux/avc.c | |
parent | selinux: fix a possible memory leak in cond_read_node() (diff) | |
download | linux-f31e799459659ae88c341aeac16a8a5efb1271d4.tar.xz linux-f31e799459659ae88c341aeac16a8a5efb1271d4.zip |
selinux: no recursive read_lock of policy_rwlock in security_genfs_sid()
With the introduction of fair queued rwlock, recursive read_lock()
may hang the offending process if there is a write_lock() somewhere
in between.
With recursive read_lock checking enabled, the following error was
reported:
=============================================
[ INFO: possible recursive locking detected ]
3.16.0-rc1 #2 Tainted: G E
---------------------------------------------
load_policy/708 is trying to acquire lock:
(policy_rwlock){.+.+..}, at: [<ffffffff8125b32a>]
security_genfs_sid+0x3a/0x170
but task is already holding lock:
(policy_rwlock){.+.+..}, at: [<ffffffff8125b48c>]
security_fs_use+0x2c/0x110
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(policy_rwlock);
lock(policy_rwlock);
This patch fixes the occurrence of recursive read_lock() of
policy_rwlock by adding a helper function __security_genfs_sid()
which requires caller to take the lock before calling it. The
security_fs_use() was then modified to call the new helper function.
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Diffstat (limited to 'security/selinux/avc.c')
0 files changed, 0 insertions, 0 deletions