From: Hui Peng <benquike@gmail.com>
To: security@kernel.org
Cc: Hui Peng <benquike@gmail.com>,
Mathias Payer <mathias.payer@nebelwelt.net>,
Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>,
alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org
Subject: [PATCH] Fix an OOB bug in uac_mixer_unit_bmControls
Date: Mon, 19 Aug 2019 18:00:04 -0400 [thread overview]
Message-ID: <20190819220005.10178-1-benquike@gmail.com> (raw)
`uac_mixer_unit_get_channels` calls `uac_mixer_unit_bmControls`
to get pointer to bmControls field. The current implementation of
`uac_mixer_unit_get_channels` does properly check the size of
uac_mixer_unit_descriptor descriptor and may allow OOB access
in `uac_mixer_unit_bmControls`.
Reported-by: Hui Peng <benquike@gmail.com>
Reported-by: Mathias Payer <mathias.payer@nebelwelt.net>
Signed-off-by: Hui Peng <benquike@gmail.com>
---
sound/usb/mixer.c | 25 ++++++++++++++++++-------
1 file changed, 18 insertions(+), 7 deletions(-)
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index b5927c3d5bc0..00e6274a63c3 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -738,28 +738,39 @@ static int get_cluster_channels_v3(struct mixer_build *state, unsigned int clust
static int uac_mixer_unit_get_channels(struct mixer_build *state,
struct uac_mixer_unit_descriptor *desc)
{
- int mu_channels;
+ int mu_channels = 0;
void *c;
- if (desc->bLength < sizeof(*desc))
- return -EINVAL;
if (!desc->bNrInPins)
return -EINVAL;
- if (desc->bLength < sizeof(*desc) + desc->bNrInPins)
- return -EINVAL;
switch (state->mixer->protocol) {
case UAC_VERSION_1:
+ // limit derived from uac_mixer_unit_bmControls
+ if (desc->bLength < sizeof(*desc) + desc->bNrInPins + 4)
+ return 0;
+
+ mu_channels = uac_mixer_unit_bNrChannels(desc);
+ break;
+
case UAC_VERSION_2:
- default:
- if (desc->bLength < sizeof(*desc) + desc->bNrInPins + 1)
+ // limit derived from uac_mixer_unit_bmControls
+ if (desc->bLength < sizeof(*desc) + desc->bNrInPins + 6)
return 0; /* no bmControls -> skip */
+
mu_channels = uac_mixer_unit_bNrChannels(desc);
break;
case UAC_VERSION_3:
+ // limit derived from uac_mixer_unit_bmControls
+ if (desc->bLength < sizeof(*desc) + desc->bNrInPins + 2)
+ return 0; /* no bmControls -> skip */
+
mu_channels = get_cluster_channels_v3(state,
uac3_mixer_unit_wClusterDescrID(desc));
break;
+
+ default:
+ break;
}
if (!mu_channels)
--
2.22.1
next reply other threads:[~2019-08-19 22:00 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-19 22:00 Hui Peng [this message]
-- strict thread matches above, loose matches on Subject: below --
2019-08-17 4:32 [PATCH] Fix an OOB bug in uac_mixer_unit_bmControls Hui Peng
2019-08-17 6:55 ` Takashi Iwai
[not found] ` <CAKpmkkW3dxfRGqCOdfRm9nXmLjqXk5hTLLonBDBJXSM0Hnu6eg@mail.gmail.com>
2019-08-17 16:18 ` Takashi Iwai
[not found] ` <CAKpmkkXNcQWxco2Zxf5rBwyt7mHHkfZ2+COtZROyKmgsq2Ch_Q@mail.gmail.com>
2019-08-17 17:59 ` Takashi Iwai
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