Bug 1334316 (CVE-2016-4568) - CVE-2016-4568 kernel: videobuf2-v412: Planes array amount not verified in buffer dequeueing
Summary: CVE-2016-4568 kernel: videobuf2-v412: Planes array amount not verified in buf...
Status: NEW
Alias: CVE-2016-4568
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard: impact=low,public=20160507,reported=2...
Keywords: Security
Depends On: 1334317
Blocks:
TreeView+ depends on / blocked
 
Reported: 2016-05-09 11:38 UTC by Andrej Nemec
Modified: 2019-02-08 15:01 UTC (History)
27 users (show)

(edit)
Clone Of:
(edit)
Last Closed:


Attachments (Terms of Use)

Description Andrej Nemec 2016-05-09 11:38:21 UTC
 When a buffer is being dequeued using VIDIOC_DQBUF IOCTL, the exact buffer which will be dequeued is not known until the buffer has been removed from the queue. The number of planes is specific to a buffer, not to the queue.
    
This does lead to the situation where multi-plane buffers may be requested and queued with n planes, but VIDIOC_DQBUF IOCTL may be passed an argument struct with fewer planes.
    
__fill_v4l2_buffer() however uses the number of planes from the dequeued videobuf2 buffer, overwriting kernel memory (the m.planes array allocated in video_usercopy() in v4l2-ioctl.c)  if the user provided fewer planes than the dequeued buffer had.

References:

http://seclists.org/oss-sec/2016/q2/272

Upstream fix:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2c1f6951a8a82e6de0d82b1158b5e493fc6c54ab

Introduced by:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b0e0e1f83de31aa0428c38b692c590cc0ecd3f03

Comment 1 Andrej Nemec 2016-05-09 11:39:26 UTC
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1334317]


Note You need to log in before you can comment on or make changes to this bug.