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
prev 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 [PATCH -next v3] nbd: add the check to prevent overflow in __nbd_ioctl() 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]
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