4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Takashi Iwai <[email protected]> commit d937cd6790a2bef2d07b500487646bd794c039bb upstream. When the usb-audio descriptor contains the malformed feature unit description with a too short length, the driver may access out-of-bounds. Add a sanity check of the header size at the beginning of parse_audio_feature_unit(). Fixes: 23caaf19b11e ("ALSA: usb-mixer: Add support for Audio Class v2.0") Reported-by: Andrey Konovalov <[email protected]> Signed-off-by: Takashi Iwai <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- sound/usb/mixer.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -1397,6 +1397,12 @@ static int parse_audio_feature_unit(stru __u8 *bmaControls; if (state->mixer->protocol == UAC_VERSION_1) { + if (hdr->bLength < 7) { + usb_audio_err(state->chip, + "unit %u: invalid UAC_FEATURE_UNIT descriptor\n", + unitid); + return -EINVAL; + } csize = hdr->bControlSize; if (!csize) { usb_audio_dbg(state->chip, @@ -1414,6 +1420,12 @@ static int parse_audio_feature_unit(stru } } else { struct uac2_feature_unit_descriptor *ftr = _ftr; + if (hdr->bLength < 6) { + usb_audio_err(state->chip, + "unit %u: invalid UAC_FEATURE_UNIT descriptor\n", + unitid); + return -EINVAL; + } csize = 4; channels = (hdr->bLength - 6) / 4 - 1; bmaControls = ftr->bmaControls;
