tree ae0c3143ac04b2374198808022ed2284de6adc32
parent a1ba8819766af43459c5aaead44dbd3b0a3fc957
author Johan Hovold <johan@kernel.org> 1578069310 +0100
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1585840838 +0200

media: stv06xx: add missing descriptor sanity checks

commit 485b06aadb933190f4bc44e006076bc27a23f205 upstream.

Make sure to check that we have two alternate settings and at least one
endpoint before accessing the second altsetting structure and
dereferencing the endpoint arrays.

This specifically avoids dereferencing NULL-pointers or corrupting
memory when a device does not have the expected descriptors.

Note that the sanity checks in stv06xx_start() and pb0100_start() are
not redundant as the driver is mixing looking up altsettings by index
and by number, which may not coincide.

Fixes: 8668d504d72c ("V4L/DVB (12082): gspca_stv06xx: Add support for st6422 bridge and sensor")
Fixes: c0b33bdc5b8d ("[media] gspca-stv06xx: support bandwidth changing")
Cc: stable <stable@vger.kernel.org>     # 2.6.31
Cc: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>