Commit d937cd67 authored by Takashi Iwai's avatar Takashi Iwai

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: 23caaf19 ("ALSA: usb-mixer: Add support for Audio Class v2.0")
Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 3d4e8303
...@@ -1469,6 +1469,12 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, ...@@ -1469,6 +1469,12 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid,
__u8 *bmaControls; __u8 *bmaControls;
if (state->mixer->protocol == UAC_VERSION_1) { 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; csize = hdr->bControlSize;
if (!csize) { if (!csize) {
usb_audio_dbg(state->chip, usb_audio_dbg(state->chip,
...@@ -1486,6 +1492,12 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, ...@@ -1486,6 +1492,12 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid,
} }
} else { } else {
struct uac2_feature_unit_descriptor *ftr = _ftr; 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; csize = 4;
channels = (hdr->bLength - 6) / 4 - 1; channels = (hdr->bLength - 6) / 4 - 1;
bmaControls = ftr->bmaControls; bmaControls = ftr->bmaControls;
......
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