From: Christoph Hellwig <hch@infradead.org>
To: Yu Kuai <yukuai1@huaweicloud.com>
Cc: axboe@kernel.dk, ming.lei@redhat.com,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
yukuai3@huawei.com, yi.zhang@huawei.com, yangerkun@huawei.com
Subject: Re: [PATCH -next] block: fix uaf for flush rq while iterating tags
Date: Tue, 5 Nov 2024 03:19:32 -0800 [thread overview]
Message-ID: <Zyn_RGV2i9COvNQl@infradead.org> (raw)
In-Reply-To: <20241104110005.1412161-1-yukuai1@huaweicloud.com>
On Mon, Nov 04, 2024 at 07:00:05PM +0800, Yu Kuai wrote:
> From: Yu Kuai <yukuai3@huawei.com>
>
> blk_mq_clear_flush_rq_mapping() is not called during scsi probe, by
> checking blk_queue_init_done(). However, QUEUE_FLAG_INIT_DONE is cleared
> in del_gendisk by commit aec89dc5d421 ("block: keep q_usage_counter in
> atomic mode after del_gendisk"), hence for disk like scsi, following
> blk_mq_destroy_queue() will not clear flush rq from tags->rqs[] as well,
> cause following uaf that is found by our syzkaller for v6.6:
Which means we leave the flush request lingering after del_gendisk,
which sounds like the real bug. I suspect we just need to move the
call to blk_mq_clear_flush_rq_mapping so that it is called from
del_gendisk and doesn't leave the flush tag lingering around.
next prev parent reply other threads:[~2024-11-05 11:19 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-04 11:00 [PATCH -next] block: fix uaf for flush rq while iterating tags Yu Kuai
2024-11-05 7:18 ` Ming Lei
2024-11-05 7:36 ` Yu Kuai
2024-11-05 7:58 ` Ming Lei
2024-11-05 8:09 ` Yu Kuai
2024-11-19 1:30 ` Yu Kuai
2024-11-05 11:19 ` Christoph Hellwig [this message]
2024-11-06 2:58 ` Yu Kuai
2024-11-06 3:11 ` Ming Lei
2024-11-06 3:25 ` Yu Kuai
2024-11-06 3:36 ` Ming Lei
2024-11-06 3:51 ` Yu Kuai
2024-11-06 3:58 ` Ming Lei
2024-11-19 1:32 ` Jens Axboe
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