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authorTakashi Iwai <tiwai@suse.de>2020-12-09 09:45:51 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-12-21 13:27:05 +0100
commite72a55ea71687483a0b1596f62a6db392d42bed3 (patch)
tree8fc947d49a73d6e50c43c8af2d13549cea4bb452 /sound/usb/format.c
parent56339afa39e54c75ce2893fee84631eff72d3fa5 (diff)
ALSA: usb-audio: Fix potential out-of-bounds shift
commit 43d5ca88dfcd35e43010fdd818e067aa9a55f5ba upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound/usb/format.c')
-rw-r--r--sound/usb/format.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/sound/usb/format.c b/sound/usb/format.c
index 1f9ea513230a..9e9d4c10dfac 100644
--- a/sound/usb/format.c
+++ b/sound/usb/format.c
@@ -40,6 +40,8 @@ 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;