[PATCH 5.15 010/139] selinux: fix misuse of mutex_is_locked()

Greg Kroah-Hartman
2022-02-28T17:51:11Z

From: Ondrej Mosnacek <omosnace@redhat.com>

commit ce2fc710c9d2b25afc710f49bb2065b4439a62bc upstream.

mutex_is_locked() tests whether the mutex is locked *by any task*, while
here we want to test if it is held *by the current task*. To avoid
false/missed WARNINGs, use lockdep_assert_is_held() and
lockdep_assert_is_not_held() instead, which do the right thing (though
they are a no-op if CONFIG_LOCKDEP=n).

Cc: stable@vger.kernel.org
Fixes: 2554a48f4437 ("selinux: measure state and policy capabilities")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
security/selinux/ima.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/security/selinux/ima.c
+++ b/security/selinux/ima.c
@@ -77,7 +77,7 @@ void selinux_ima_measure_state_locked(st
size_t policy_len;
int rc = 0;

- WARN_ON(!mutex_is_locked(&state->policy_mutex));
+ lockdep_assert_held(&state->policy_mutex);

state_str = selinux_ima_collect_state(state);
if (!state_str) {
@@ -117,7 +117,7 @@ void selinux_ima_measure_state_locked(st
*/
void selinux_ima_measure_state(struct selinux_state *state)
{
- WARN_ON(mutex_is_locked(&state->policy_mutex));
+ lockdep_assert_not_held(&state->policy_mutex);

mutex_lock(&state->policy_mutex);
selinux_ima_measure_state_locked(state);