From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Li Jinlin <lijinlin3@huawei.com>, Jens Axboe <axboe@kernel.dk>,
Sasha Levin <sashal@kernel.org>,
tj@kernel.org, cgroups@vger.kernel.org,
linux-block@vger.kernel.org
Subject: [PATCH AUTOSEL 4.19 4/4] blk-throttle: fix UAF by deleteing timer in blk_throtl_exit()
Date: Thu, 16 Sep 2021 22:34:57 -0400 [thread overview]
Message-ID: <20210917023457.816816-4-sashal@kernel.org> (raw)
In-Reply-To: <20210917023457.816816-1-sashal@kernel.org>
From: Li Jinlin <lijinlin3@huawei.com>
[ Upstream commit 884f0e84f1e3195b801319c8ec3d5774e9bf2710 ]
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: Li Jinlin <lijinlin3@huawei.com>
Link: https://lore.kernel.org/r/20210907121242.2885564-1-lijinlin3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
block/blk-throttle.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index caee658609d7..853b1770df36 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -2437,6 +2437,7 @@ 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]);
--
2.30.2
parent reply other threads:[~2021-09-17 2:36 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <20210917023457.816816-1-sashal@kernel.org>]
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