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From: Christoph Hellwig <hch@lst.de>
To: Hillf Danton <hdanton@sina.com>
Cc: syzbot <syzbot+2c98885bcd769f56b6d6@syzkaller.appspotmail.com>,
	axboe@kernel.dk, josef@toxicpanda.com,
	linux-block@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
	linux-kernel@vger.kernel.org, nbd@other.debian.org,
	syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] KASAN: use-after-free Read in nbd_genl_connect (2)
Date: Wed, 25 Aug 2021 11:27:31 +0200	[thread overview]
Message-ID: <20210825092731.GA1328@lst.de> (raw)
In-Reply-To: <20210825085525.2147-1-hdanton@sina.com>

On Wed, Aug 25, 2021 at 04:55:25PM +0800, Hillf Danton wrote:
> Because no nbd is kfreed without being removed from the nbd idr, finding
> a freed nbd in the idr with nbd_index_mutex held means the nbd is not a
> valid pointer, and fix the uaf by cutting the chance for invalid nbd.
> 
> Only for thoughts now.

That is a bug, but not really the problem here.  I think the issue
is the completion issue that Tetsuo reported.  Looking into that at
the moment.

      parent reply	other threads:[~2021-08-25  9:27 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-25  7:12 [syzbot] KASAN: use-after-free Read in nbd_genl_connect (2) syzbot
     [not found] ` <20210825085525.2147-1-hdanton@sina.com>
2021-08-25  9:27   ` Christoph Hellwig [this message]

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