From: Christoph Hellwig <hch@infradead.org>
To: Edward Adam Davis <eadavis@qq.com>
Cc: syzbot+a2b9a4ed0d61b1efb3f5@syzkaller.appspotmail.com,
brauner@kernel.org, djwong@kernel.org,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-xfs@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: Re: [PATCH Next] iomap: Add sanity check for dio done workqueue
Date: Mon, 24 Nov 2025 01:18:09 -0800 [thread overview]
Message-ID: <aSQi0e8SmY5OVLcS@infradead.org> (raw)
In-Reply-To: <tencent_734A1B432559BAF7BBA333429E581B034B08@qq.com>
On Mon, Nov 24, 2025 at 04:53:04PM +0800, Edward Adam Davis wrote:
> The s_dio_done_wq was not allocated memory, leading to the null-ptr-deref
> reported by syzbot in [1].
>
> As shown in [1], we are currently in a soft interrupt context, and we cannot
> use sb_init_dio_done_wq() to allocate memory for wq because it requires a
> mutex lock.
>
> Added a check to the workqueue; if it is empty, it switches to using a
> synchronous method to end the dio.
Err no. That sanity check doesn't do anything useful. Whatever caused
it to be not allocated and allow I/O needs to be fixed. And I suspect
it's my fault and I already have an idea how to fix, so don't rush it.
next prev parent reply other threads:[~2025-11-24 9:18 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-24 0:01 [syzbot] [iomap?] general protection fault in iomap_dio_bio_end_io syzbot
2025-11-24 8:53 ` [PATCH Next] iomap: Add sanity check for dio done workqueue Edward Adam Davis
2025-11-24 9:18 ` Christoph Hellwig [this message]
2025-11-24 9:30 ` [syzbot] [iomap?] general protection fault in iomap_dio_bio_end_io Christoph Hellwig
2025-11-24 12:49 ` syzbot
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