From: Takashi Iwai <tiwai@suse.de>
To: alsa-devel@alsa-project.org
Subject: [PATCH 1/2] ALSA: usb-audio: Fix potential out-of-bounds shift
Date: Wed, 9 Dec 2020 09:45:51 +0100 [thread overview]
Message-ID: <20201209084552.17109-1-tiwai@suse.de> (raw)
syzbot spotted a potential out-of-bounds shift in the USB-audio format
parser that receives the arbitrary shift value from the USB
descriptor.
Add a range check for avoiding the undefined behavior.
Reported-by: syzbot+df7dc146ebdd6435eea3@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
sound/usb/format.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/sound/usb/format.c b/sound/usb/format.c
index 93459ba228d3..9ebc5d202c87 100644
--- a/sound/usb/format.c
+++ b/sound/usb/format.c
@@ -39,6 +39,8 @@ static u64 parse_audio_format_i_type(struct snd_usb_audio *chip,
case UAC_VERSION_1:
default: {
struct uac_format_type_i_discrete_descriptor *fmt = _fmt;
+ if (format >= 64)
+ return 0; /* invalid format */
sample_width = fmt->bBitResolution;
sample_bytes = fmt->bSubframeSize;
format = 1ULL << format;
--
2.26.2
next reply other threads:[~2020-12-09 8:47 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-09 8:45 Takashi Iwai [this message]
2020-12-09 8:45 ` [PATCH 2/2] ALSA: pcm: oss: Fix potential out-of-bounds shift Takashi Iwai
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