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| author | Takashi Iwai <tiwai@suse.de> | 2020-12-09 09:45:51 +0100 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2020-12-14 09:10:25 +0100 |
| commit | 43d5ca88dfcd35e43010fdd818e067aa9a55f5ba (patch) | |
| tree | 8525fc0223f857d2c48057c2b066784b0a224fcf | |
| parent | e5fab13a7c54b8e69ea3bb27067eb06aba5f19b5 (diff) | |
| download | linux-43d5ca88dfcd35e43010fdd818e067aa9a55f5ba.tar.bz2 | |
ALSA: usb-audio: Fix potential out-of-bounds shift
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>
Link: https://lore.kernel.org/r/20201209084552.17109-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
| -rw-r--r-- | sound/usb/format.c | 2 |
1 files changed, 2 insertions, 0 deletions
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; |