From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Pavel Begunkov <asml.silence@gmail.com>,
syzbot+cb265db2f3f3468ef436@syzkaller.appspotmail.com,
Jens Axboe <axboe@kernel.dk>, Sasha Levin <sashal@kernel.org>,
io-uring@vger.kernel.org
Subject: [PATCH AUTOSEL 6.3 02/14] io_uring: annotate offset timeout races
Date: Sun, 2 Jul 2023 15:40:41 -0400 [thread overview]
Message-ID: <20230702194053.1777356-2-sashal@kernel.org> (raw)
In-Reply-To: <20230702194053.1777356-1-sashal@kernel.org>
From: Pavel Begunkov <asml.silence@gmail.com>
[ Upstream commit 5498bf28d8f2bd63a46ad40f4427518615fb793f ]
It's racy to read ->cached_cq_tail without taking proper measures
(usually grabbing ->completion_lock) as timeout requests with CQE
offsets do, however they have never had a good semantics for from
when they start counting. Annotate racy reads with data_race().
Reported-by: syzbot+cb265db2f3f3468ef436@syzkaller.appspotmail.com
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4de3685e185832a92a572df2be2c735d2e21a83d.1684506056.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
io_uring/timeout.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/io_uring/timeout.c b/io_uring/timeout.c
index 826a51bca3e49..495eeaebce0c0 100644
--- a/io_uring/timeout.c
+++ b/io_uring/timeout.c
@@ -543,7 +543,7 @@ int io_timeout(struct io_kiocb *req, unsigned int issue_flags)
goto add;
}
- tail = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
+ tail = data_race(ctx->cached_cq_tail) - atomic_read(&ctx->cq_timeouts);
timeout->target_seq = tail + off;
/* Update the last seq here in case io_flush_timeouts() hasn't.
--
2.39.2
next prev parent reply other threads:[~2023-07-02 19:43 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-02 19:40 [PATCH AUTOSEL 6.3 01/14] cpu/hotplug: Reset task stack state in _cpu_up() Sasha Levin
2023-07-02 19:40 ` Sasha Levin [this message]
2023-07-02 19:40 ` [PATCH AUTOSEL 6.3 03/14] x86/amd_nb: Add MI200 PCI IDs Sasha Levin
2023-07-02 19:40 ` [PATCH AUTOSEL 6.3 04/14] debugobjects: Recheck debug_objects_enabled before reporting Sasha Levin
2023-07-02 19:40 ` [PATCH AUTOSEL 6.3 05/14] nbd: Add the maximum limit of allocated index in nbd_dev_add Sasha Levin
2023-07-02 19:40 ` [PATCH AUTOSEL 6.3 06/14] md: fix data corruption for raid456 when reshape restart while grow up Sasha Levin
2023-07-02 19:40 ` [PATCH AUTOSEL 6.3 07/14] md/raid10: prevent soft lockup while flush writes Sasha Levin
2023-07-02 19:40 ` [PATCH AUTOSEL 6.3 08/14] scsi: sg: fix blktrace debugfs entries leakage Sasha Levin
2023-07-02 19:40 ` [PATCH AUTOSEL 6.3 09/14] blk-mq: fix NULL dereference on q->elevator in blk_mq_elv_switch_none Sasha Levin
2023-07-02 19:40 ` [PATCH AUTOSEL 6.3 10/14] posix-timers: Ensure timer ID search-loop limit is valid Sasha Levin
2023-07-02 19:40 ` [PATCH AUTOSEL 6.3 11/14] btrfs: add xxhash to fast checksum implementations Sasha Levin
2023-07-02 19:40 ` [PATCH AUTOSEL 6.3 12/14] btrfs: don't check PageError in __extent_writepage Sasha Levin
2023-07-02 19:40 ` [PATCH AUTOSEL 6.3 13/14] btrfs: abort transaction at update_ref_for_cow() when ref count is zero Sasha Levin
2023-07-02 19:40 ` [PATCH AUTOSEL 6.3 14/14] erofs: Fix detection of atomic context Sasha Levin
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