Fix unbalanced helper_lock in kernel/kmod.c
call_usermodehelper_exec() has an exit path that can leave the
helper_lock() call at the top of the routine unbalanced. The attached
patch fixes this issue.
Signed-off-by: Nigel Cunningham <nigel@tuxonice.net>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/kmod.c b/kernel/kmod.c
index c6a4f8a..bb7df2a 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -451,13 +451,11 @@
enum umh_wait wait)
{
DECLARE_COMPLETION_ONSTACK(done);
- int retval;
+ int retval = 0;
helper_lock();
- if (sub_info->path[0] == '\0') {
- retval = 0;
+ if (sub_info->path[0] == '\0')
goto out;
- }
if (!khelper_wq || usermodehelper_disabled) {
retval = -EBUSY;
@@ -468,13 +466,14 @@
sub_info->wait = wait;
queue_work(khelper_wq, &sub_info->work);
- if (wait == UMH_NO_WAIT) /* task has freed sub_info */
- return 0;
+ if (wait == UMH_NO_WAIT) /* task has freed sub_info */
+ goto unlock;
wait_for_completion(&done);
retval = sub_info->retval;
- out:
+out:
call_usermodehelper_freeinfo(sub_info);
+unlock:
helper_unlock();
return retval;
}