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Date:   Fri, 5 Jun 2020 16:42:36 +0200
From:   Jan Kara <jack@suse.cz>
To:     Dan Carpenter <dan.carpenter@oracle.com>
Cc:     Jason Yan <yanaijie@huawei.com>, Jan Kara <jack@suse.cz>,
        Markus Elfring <Markus.Elfring@web.de>,
        linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        hulkci@huawei.com, kernel-janitors@vger.kernel.org,
        linux-kernel@vger.kernel.org, Al Viro <viro@zeniv.linux.org.uk>,
        Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
        Ming Lei <ming.lei@redhat.com>
Subject: Re: [PATCH v2] block: Fix use-after-free in blkdev_get()
Message-ID: <20200605144236.GB13248@quack2.suse.cz>
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 <20200605094353.GS30374@kadam>
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On Fri 05-06-20 12:43:54, Dan Carpenter wrote:
> I wonder if maybe the best fix is to re-add the "if (!res) " check back
> to blkdev_get().

Well, it won't be that simple since we need to call bd_abort_claiming()
under bdev->bd_mutex. And the fact that __blkdev_get() frees the reference
you pass to it is somewhat subtle and surprising so I think we are better
off getting rid of that.

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR