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Commit 78468033 authored by Nigel Cunningham's avatar Nigel Cunningham Committed by Linus Torvalds
Browse files

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: default avatarNigel Cunningham <nigel@tuxonice.net>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 34aebfd3

kernel/kmod.c

+6 −7
Original line number Diff line number Diff line
@@ -451,13 +451,11 @@ int call_usermodehelper_exec(struct subprocess_info *sub_info, 
			     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;
@@ -469,12 +467,13 @@ int call_usermodehelper_exec(struct subprocess_info *sub_info, 


	queue_work(khelper_wq, &sub_info->work);

	if (wait == UMH_NO_WAIT)	/* task has freed sub_info */

		return 0;

		goto unlock;

	wait_for_completion(&done);

	retval = sub_info->retval;



out:

	call_usermodehelper_freeinfo(sub_info);

unlock:

	helper_unlock();

	return retval;

}