diff options
| author | Takashi Iwai <tiwai@suse.de> | 2018-12-19 12:36:27 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-13 10:05:32 +0100 |
| commit | a5e09a908ea3c64bf522822b7923d2d8fc1a7af2 (patch) | |
| tree | 77c0dd01381335cce8d5680ad6a62a7943cf57fa /sound | |
| parent | 83f470ebd75e3fbe56e177763337dc9326af02a4 (diff) | |
ALSA: usb-audio: Avoid access before bLength check in build_audio_procunit()
commit f4351a199cc120ff9d59e06d02e8657d08e6cc46 upstream.
The parser for the processing unit reads bNrInPins field before the
bLength sanity check, which may lead to an out-of-bound access when a
malformed descriptor is given. Fix it by assignment after the bLength
check.
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/usb/mixer.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 97d6a18e6956..f7eb0d2f797b 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -1816,7 +1816,7 @@ static int build_audio_procunit(struct mixer_build *state, int unitid, char *name) { struct uac_processing_unit_descriptor *desc = raw_desc; - int num_ins = desc->bNrInPins; + int num_ins; struct usb_mixer_elem_info *cval; struct snd_kcontrol *kctl; int i, err, nameid, type, len; @@ -1831,7 +1831,13 @@ static int build_audio_procunit(struct mixer_build *state, int unitid, 0, NULL, default_value_info }; - if (desc->bLength < 13 || desc->bLength < 13 + num_ins || + if (desc->bLength < 13) { + usb_audio_err(state->chip, "invalid %s descriptor (id %d)\n", name, unitid); + return -EINVAL; + } + + num_ins = desc->bNrInPins; + if (desc->bLength < 13 + num_ins || desc->bLength < num_ins + uac_processing_unit_bControlSize(desc, state->mixer->protocol)) { usb_audio_err(state->chip, "invalid %s descriptor (id %d)\n", name, unitid); return -EINVAL; |