From: Jens Axboe <axboe@kernel.dk>
To: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
Johannes Thumshirn <jthumshirn@suse.de>
Subject: Re: [PATCH v2] block: fix possible NULL dereference
Date: Fri, 1 Apr 2016 08:38:23 -0600 [thread overview]
Message-ID: <56FE87DF.3000603@kernel.dk> (raw)
In-Reply-To: <1459521258-18534-1-git-send-email-sudipm.mukherjee@gmail.com>
On 04/01/2016 08:34 AM, Sudip Mukherjee wrote:
> We were checking for iter to be NULL after dereferencing it. There is
> actually no need to check for iter to be NULL as all the callers of
> blk_rq_map_user_iov() does call it with a valid pointer to
> struct iov_iter.
> But as iter->count can be NULL so the assignment to copy is being done
> after checking for it.
>
> Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
> ---
>
> v2: removed the check for iter
> v1: moved the assignment to copy after check for iter and iter->count
Your subject is wrong (there's no NULL deref). Ditto for the commit
message - it can be zero, not NULL. The latter would imply a memory
address, but it's just an integer.
--
Jens Axboe
next prev parent reply other threads:[~2016-04-01 14:38 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-01 14:34 [PATCH v2] block: fix possible NULL dereference Sudip Mukherjee
2016-04-01 14:38 ` Jens Axboe [this message]
2016-04-01 15:18 ` Sudip Mukherjee
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