linux-kernel - Re: [PATCH v2] [media] v4l2-common: fix overflow in v4l_bound_align

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20140910171013.GA14048@kroah.com>
Date:	Wed, 10 Sep 2014 10:10:13 -0700
From:	Greg KH <greg@...ah.com>
To:	Maciej Matraszek <m.matraszek@...sung.com>
Cc:	linux-media@...r.kernel.org, linux-kernel@...r.kernel.org,
	Mauro Carvalho Chehab <m.chehab@...sung.com>,
	Hans Verkuil <hans.verkuil@...co.com>,
	Lars-Peter Clausen <lars@...afoo.de>,
	Sylwester Nawrocki <s.nawrocki@...sung.com>,
	stable@...r.kernel.org,
	Krzysztof Kozlowski <k.kozlowski@...sung.com>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
	Sakari Ailus <sakari.ailus@...ux.intel.com>
Subject: Re: [PATCH v2] [media] v4l2-common: fix overflow in
 v4l_bound_align_image()

On Wed, Sep 10, 2014 at 06:51:09PM +0200, Maciej Matraszek wrote:
> Fix clamp_align() used in v4l_bound_align_image() to prevent overflow when
> passed large value like UINT32_MAX. In the current implementation:
>     clamp_align(UINT32_MAX, 8, 8192, 3)
> returns 8, because in line:
>     x = (x + (1 << (align - 1))) & mask;
> x overflows to (-1 + 4) & 0x7 = 3, while expected value is 8192.
> 
> v4l_bound_align_image() is heavily used in VIDIOC_S_FMT
> and VIDIOC_SUBDEV_S_FMT ioctls handlers, and documentation of the latter
> explicitly states that:
> 
> "The modified format should be as close as possible to the original request."
>   -- http://linuxtv.org/downloads/v4l-dvb-apis/vidioc-subdev-g-fmt.html
> 
> Thus one would expect, that passing UINT32_MAX as format width and height
> will result in setting maximum possible resolution for the device.
> Particularly, when the driver doesn't support VIDIOC_ENUM_FRAMESIZES ioctl,
> which is common in the codebase.
> 
> Fixes: b0d3159be9a3 ("V4L/DVB (11901): v4l2: Create helper function for bounding and aligning images")
> Signed-off-by: Maciej Matraszek <m.matraszek@...sung.com>
> Acked-by: Sakari Ailus <sakari.ailus@...ux.intel.com>
> 
> ---

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read Documentation/stable_kernel_rules.txt
for how to do this properly.

</formletter>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/