LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Jens Axboe <axboe@kernel.dk>
To: Baokun Li <libaokun1@huawei.com>,
	josef@toxicpanda.com, linux-block@vger.kernel.org,
	nbd@other.debian.org, linux-kernel@vger.kernel.org
Cc: patchwork@huawei.com, yukuai3@huawei.com, Hulk Robot <hulkci@huawei.com>
Subject: Re: [PATCH -next v3] nbd: add the check to prevent overflow in __nbd_ioctl()
Date: Fri, 13 Aug 2021 13:09:23 -0600	[thread overview]
Message-ID: <1799b798-34dc-9589-72d8-367516daf7ee@kernel.dk> (raw)
In-Reply-To: <20210804021212.990223-1-libaokun1@huawei.com>

On 8/3/21 8:12 PM, Baokun Li wrote:
> If user specify a large enough value of NBD blocks option, it may trigger
> signed integer overflow which may lead to nbd->config->bytesize becomes a
> large or small value, zero in particular.
> 
> UBSAN: Undefined behaviour in drivers/block/nbd.c:325:31
> signed integer overflow:
> 1024 * 4611686155866341414 cannot be represented in type 'long long int'
> [...]
> Call trace:
> [...]
>  handle_overflow+0x188/0x1dc lib/ubsan.c:192
>  __ubsan_handle_mul_overflow+0x34/0x44 lib/ubsan.c:213
>  nbd_size_set drivers/block/nbd.c:325 [inline]
>  __nbd_ioctl drivers/block/nbd.c:1342 [inline]
>  nbd_ioctl+0x998/0xa10 drivers/block/nbd.c:1395
>  __blkdev_driver_ioctl block/ioctl.c:311 [inline]
> [...]
> 
> Although it is not a big deal, still silence the UBSAN by limit
> the input value.

Applied with unlikely() removed.

-- 
Jens Axboe


      parent reply	other threads:[~2021-08-13 19:09 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-04  2:12 Baokun Li
2021-08-12  1:55 ` libaokun (A)
2021-08-13 15:53 ` Josef Bacik
2021-08-13 19:09 ` Jens Axboe [this message]

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=1799b798-34dc-9589-72d8-367516daf7ee@kernel.dk \
    --to=axboe@kernel.dk \
    --cc=hulkci@huawei.com \
    --cc=josef@toxicpanda.com \
    --cc=libaokun1@huawei.com \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=nbd@other.debian.org \
    --cc=patchwork@huawei.com \
    --cc=yukuai3@huawei.com \
    --subject='Re: [PATCH -next v3] nbd: add the check to prevent overflow in __nbd_ioctl()' \
    /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

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).