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| author | Hui Peng <benquike@gmail.com> | 2019-08-13 22:34:04 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-08-25 10:47:47 +0200 |
| commit | 58b9f19ee438990f6406e61943d0bc7c875a0921 (patch) | |
| tree | 39ba01697cdebf7baa05db158f6efd883026dc03 /sound | |
| parent | 46f9a1bc60a4c15a14a6504168cee1c2e0bf3ab4 (diff) | |
| download | linux-stable-58b9f19ee438990f6406e61943d0bc7c875a0921.tar.gz linux-stable-58b9f19ee438990f6406e61943d0bc7c875a0921.tar.bz2 linux-stable-58b9f19ee438990f6406e61943d0bc7c875a0921.zip | |
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 | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 996126a28072..4b3e1c48ca2f 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -760,6 +760,8 @@ static int uac_mixer_unit_get_channels(struct mixer_build *state, return -EINVAL; if (!desc->bNrInPins) return -EINVAL; + if (desc->bLength < sizeof(*desc) + desc->bNrInPins) + return -EINVAL; switch (state->mixer->protocol) { case UAC_VERSION_1: |