block: fix use-after-free bug in blk throttle code

blk_throtl_exit() frees the throttle data hanging off the queue
in blk_cleanup_queue(), but blk_put_queue() will indirectly
dereference this data when calling blk_sync_queue() which in
turns calls throtl_shutdown_timer_wq().

Fix this by moving the freeing of the throttle data to when
the queue is truly being released, and post the call to
blk_sync_queue().

Reported-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This commit is contained in:
Jens Axboe 2010-10-23 20:40:26 +02:00
parent 7f38839628
commit 7ad58c0286
2 changed files with 2 additions and 2 deletions

View file

@ -462,8 +462,6 @@ void blk_cleanup_queue(struct request_queue *q)
if (q->elevator)
elevator_exit(q->elevator);
blk_throtl_exit(q);
blk_put_queue(q);
}
EXPORT_SYMBOL(blk_cleanup_queue);

View file

@ -471,6 +471,8 @@ static void blk_release_queue(struct kobject *kobj)
blk_sync_queue(q);
blk_throtl_exit(q);
if (rl->rq_pool)
mempool_destroy(rl->rq_pool);