It's been reported that the recent kernel can't probe the PCM devices on Roland VS-100 properly, and it turned out to be a regression by the recent addition of the bit shift range check for the format bits. In the old code, we just did bit-shift and it resulted in zero, which is then corrected to the standard PCM format, while the new code explicitly returns an error in such a case.
For addressing the regression, relax the check and fallback to the standard PCM type (with the info output).
Fixes: 43d5ca88dfcd ("ALSA: usb-audio: Fix potential out-of-bounds shift") Cc: stable@vger.kernel.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=217084 Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/usb/format.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/sound/usb/format.c b/sound/usb/format.c index 405dc0bf6678..4b1c5ba121f3 100644 --- a/sound/usb/format.c +++ b/sound/usb/format.c @@ -39,8 +39,12 @@ 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 */ + if (format >= 64) { + usb_audio_info(chip, + "%u:%d: invalid format type 0x%llx is detected, processed as PCM\n", + fp->iface, fp->altsetting, format); + format = UAC_FORMAT_TYPE_I_PCM; + } sample_width = fmt->bBitResolution; sample_bytes = fmt->bSubframeSize; format = 1ULL << format;