Michal Srb b3ad99ed45 drm/i915/cmdparser: Do not check past the cmd length.
The command MEDIA_VFE_STATE checks bits at offset +2 dwords. However, it is
possible to have MEDIA_VFE_STATE command with length = 0 + LENGTH_BIAS = 2.
In that case check_cmd will read bits from the following command, or even past
the end of the buffer.

If the offset ends up outside of the command length, reject the command.

Fixes: 351e3db2b363 ("drm/i915: Implement command buffer parsing logic")
Signed-off-by: Michal Srb <msrb@suse.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180205151745.29292-1-msrb@suse.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180205160438.3267-2-chris@chris-wilson.co.uk
(cherry picked from commit 3aec7f871c65eb5f76b4125fda432593c834a6f2)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2018-02-06 11:41:40 -08:00
..
2017-12-21 14:52:36 +01:00