Matthew Robbetts wrote:
> Is this bug fixed upstream at this point?
This patch is still untested:
--8<----------------------------------------------------------------->8--
ALSA: usb-audio: fix invalid length check for RME and other UAC 2 devices
Commit 23caaf19b11e (ALSA: usb-mixer: Add support for Audio Class v2.0)
forgot to adjust the length check for UAC 2.0 feature unit descriptors.
This would make the code abort on encountering a feature unit without
per-channel controls, and thus prevented the driver to work with any
device having such a unit, such as the RME Fireface UCX.
Reported-by: Florian Hanisch <fhani...@uni-potsdam.de>
Cc: Daniel Mack <dan...@caiaq.de>
Cc: 2.6.35+ <sta...@vger.kernel.org>
Signed-off-by: Clemens Ladisch <clem...@ladisch.de>
---
sound/usb/mixer.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 298070e..41e8bfb 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -1259,16 +1259,23 @@ static int parse_audio_feature_unit(struct mixer_build
*state, int unitid, void
}
channels = (hdr->bLength - 7) / csize - 1;
bmaControls = hdr->bmaControls;
+ if (hdr->bLength < 7 + csize) {
+ snd_printk(KERN_ERR "usbaudio: unit %u: "
+ "invalid UAC_FEATURE_UNIT descriptor\n",
+ unitid);
+ return -EINVAL;
+ }
} else {
struct uac2_feature_unit_descriptor *ftr = _ftr;
csize = 4;
channels = (hdr->bLength - 6) / 4 - 1;
bmaControls = ftr->bmaControls;
- }
-
- if (hdr->bLength < 7 || !csize || hdr->bLength < 7 + csize) {
- snd_printk(KERN_ERR "usbaudio: unit %u: invalid
UAC_FEATURE_UNIT descriptor\n", unitid);
- return -EINVAL;
+ if (hdr->bLength < 6 + csize) {
+ snd_printk(KERN_ERR "usbaudio: unit %u: "
+ "invalid UAC_FEATURE_UNIT descriptor\n",
+ unitid);
+ return -EINVAL;
+ }
}
/* parse the source unit */
------------------------------------------------------------------------------
LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial
Remotely access PCs and mobile devices and provide instant support
Improve your efficiency, and focus on delivering more value-add services
Discover what IT Professionals Know. Rescue delivers
http://p.sf.net/sfu/logmein_12329d2d
_______________________________________________
Alsa-user mailing list
Alsa-user@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/alsa-user
