From: Takashi Iwai <tiwai@xxxxxxx>
commit 976a68f06b2ea49e2ab67a5f84919a8b105db8be upstream.
The recently introduced unit descriptor validation had some bug for
processing and extension units, it counts a bControlSize byte twice so
it expected a bigger size than it should have been. This seems
resulting in a probe error on a few devices.
Fix the calculation for proper checks of PU and EU.
Fixes: 57f8770620e9 ("ALSA: usb-audio: More validations of descriptor units")
Cc: <stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20191114165613.7422-1-tiwai@xxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
sound/usb/validate.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/sound/usb/validate.c
+++ b/sound/usb/validate.c
@@ -81,9 +81,9 @@ static bool validate_processing_unit(con
switch (v->protocol) {
case UAC_VERSION_1:
default:
- /* bNrChannels, wChannelConfig, iChannelNames, bControlSize */
- len += 1 + 2 + 1 + 1;
- if (d->bLength < len) /* bControlSize */
+ /* bNrChannels, wChannelConfig, iChannelNames */
+ len += 1 + 2 + 1;
+ if (d->bLength < len + 1) /* bControlSize */
return false;
m = hdr[len];
len += 1 + m + 1; /* bControlSize, bmControls, iProcessing */
