From d937cd6790a2bef2d07b500487646bd794c039bb Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 21 Nov 2017 16:55:51 +0100 Subject: [PATCH] ALSA: usb-audio: Add sanity checks to FE parser 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 Cc: Signed-off-by: Takashi Iwai --- sound/usb/mixer.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 1beb5b4..b8ce651 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -1469,6 +1469,12 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, __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, @@ -1486,6 +1492,12 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, } } 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; -- 2.7.4