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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=56FE87DF.3000603@kernel.dk \
--to=axboe@kernel.dk \
--cc=jthumshirn@suse.de \
--cc=linux-block@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=sudipm.mukherjee@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.