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author | Takashi Iwai <tiwai@suse.de> | 2017-11-21 16:55:51 +0100 |
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committer | Takashi Iwai <tiwai@suse.de> | 2017-11-21 17:50:29 +0100 |
commit | d937cd6790a2bef2d07b500487646bd794c039bb (patch) | |
tree | c4bb62fe1c2cdcec12c0ed4a9725e19545b1e540 | |
parent | 3d4e8303f2c747c8540a0a0126d0151514f6468b (diff) | |
download | linux-d937cd6790a2bef2d07b500487646bd794c039bb.tar.gz linux-d937cd6790a2bef2d07b500487646bd794c039bb.tar.bz2 linux-d937cd6790a2bef2d07b500487646bd794c039bb.zip |
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 <andreyknvl@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
-rw-r--r-- | sound/usb/mixer.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 1beb5b4d027e..b8ce651e392c 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; |