diff options
| author | Hui Peng <benquike@gmail.com> | 2019-08-13 22:34:04 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-09-06 10:20:49 +0200 |
| commit | 96b0e80b6d5fb88c4f5b1e9d5224f2aa56395926 (patch) | |
| tree | 225245b4f0729be89d12d4d714df91a401909d65 /sound | |
| parent | 6e1a602dfd51709538fc371d053708934909e3ba (diff) | |
ALSA: usb-audio: Fix an OOB bug in parse_audio_mixer_unit
commit daac07156b330b18eb5071aec4b3ddca1c377f2c upstream.
The `uac_mixer_unit_descriptor` shown as below is read from the
device side. In `parse_audio_mixer_unit`, `baSourceID` field is
accessed from index 0 to `bNrInPins` - 1, the current implementation
assumes that descriptor is always valid (the length of descriptor
is no shorter than 5 + `bNrInPins`). If a descriptor read from
the device side is invalid, it may trigger out-of-bound memory
access.
```
struct uac_mixer_unit_descriptor {
__u8 bLength;
__u8 bDescriptorType;
__u8 bDescriptorSubtype;
__u8 bUnitID;
__u8 bNrInPins;
__u8 baSourceID[];
}
```
This patch fixes the bug by add a sanity check on the length of
the descriptor.
Reported-by: Hui Peng <benquike@gmail.com>
Reported-by: Mathias Payer <mathias.payer@nebelwelt.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Hui Peng <benquike@gmail.com>
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 | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 6d82fe34ddc0..5d48f8e74c56 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -1719,6 +1719,7 @@ static int parse_audio_mixer_unit(struct mixer_build *state, int unitid, int pin, ich, err; if (desc->bLength < 11 || !(input_pins = desc->bNrInPins) || + desc->bLength < sizeof(*desc) + desc->bNrInPins || !(num_outs = uac_mixer_unit_bNrChannels(desc))) { usb_audio_err(state->chip, "invalid MIXER UNIT descriptor %d\n", |