ALSA: usb-audio: Fix potential out-of-bounds shift
commit 43d5ca88df
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>
5.4-rM2-2.2.x-imx-squashed
parent
56339afa39
commit
e72a55ea71
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@ -40,6 +40,8 @@ static u64 parse_audio_format_i_type(struct snd_usb_audio *chip,
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case UAC_VERSION_1:
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default: {
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struct uac_format_type_i_discrete_descriptor *fmt = _fmt;
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if (format >= 64)
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return 0; /* invalid format */
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sample_width = fmt->bBitResolution;
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sample_bytes = fmt->bSubframeSize;
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format = 1ULL << format;
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