From: Jens Axboe <axboe@kernel.dk>
To: syzbot <syzbot+c74fea926a78b8a91042@syzkaller.appspotmail.com>,
Gabriel Krisman Bertazi <krisman@suse.de>
Cc: asml.silence@gmail.com, io-uring@vger.kernel.org,
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: Re: [PATCH] io_uring: Don't set affinity on a dying sqpoll thread
Date: Tue, 29 Aug 2023 11:37:08 -0600 [thread overview]
Message-ID: <169333062825.97232.1128295374932647568.b4-ty@kernel.dk> (raw)
In-Reply-To: <87v8cybuo6.fsf@suse.de>
On Mon, 28 Aug 2023 19:42:49 -0400, Gabriel Krisman Bertazi wrote:
> Syzbot reported a null-ptr-deref of sqd->thread inside
> io_sqpoll_wq_cpu_affinity. It turns out the sqd->thread can go away
> from under us during io_uring_register, in case the process gets a
> fatal signal during io_uring_register.
>
> It is not particularly hard to hit the race, and while I am not sure
> this is the exact case hit by syzbot, it solves it. Finally, checking
> ->thread is enough to close the race because we locked sqd while
> "parking" the thread, thus preventing it from going away.
>
> [...]
Applied, thanks!
[1/1] io_uring: Don't set affinity on a dying sqpoll thread
commit: 37b1499057f61de370dbd8f0c296274ab7186605
Best regards,
--
Jens Axboe
prev parent reply other threads:[~2023-08-29 17:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-28 9:59 [syzbot] [io-uring?] general protection fault in io_sqpoll_wq_cpu_affinity syzbot
2023-08-28 23:42 ` [PATCH] io_uring: Don't set affinity on a dying sqpoll thread Gabriel Krisman Bertazi
2023-08-29 13:21 ` Pavel Begunkov
2023-08-29 14:04 ` Jens Axboe
2023-08-29 17:37 ` Jens Axboe [this message]
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