Commit 884f0e84 authored by Li Jinlin's avatar Li Jinlin Committed by Jens Axboe
Browse files

blk-throttle: fix UAF by deleteing timer in blk_throtl_exit() 



The pending timer has been set up in blk_throtl_init(). However, the
timer is not deleted in blk_throtl_exit(). This means that the timer
handler may still be running after freeing the timer, which would
result in a use-after-free.

Fix by calling del_timer_sync() to delete the timer in blk_throtl_exit().

Signed-off-by: default avatarLi Jinlin <lijinlin3@huawei.com>
Link: https://lore.kernel.org/r/20210907121242.2885564-1-lijinlin3@huawei.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent dfbb3409

block/blk-throttle.c

+1 −0
Original line number Diff line number Diff line
@@ -2458,6 +2458,7 @@ int blk_throtl_init(struct request_queue *q) 
void blk_throtl_exit(struct request_queue *q)

{

	BUG_ON(!q->td);

	del_timer_sync(&q->td->service_queue.pending_timer);

	throtl_shutdown_wq(q);

	blkcg_deactivate_policy(q, &blkcg_policy_throtl);

	free_percpu(q->td->latency_buckets[READ]);