From: Takashi Iwai tiwai@suse.de
commit 976a68f06b2ea49e2ab67a5f84919a8b105db8be upstream.
The recently introduced unit descriptor validation had some bug for processing and extension units, it counts a bControlSize byte twice so it expected a bigger size than it should have been. This seems resulting in a probe error on a few devices.
Fix the calculation for proper checks of PU and EU.
Fixes: 57f8770620e9 ("ALSA: usb-audio: More validations of descriptor units") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20191114165613.7422-1-tiwai@suse.de Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- sound/usb/validate.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/sound/usb/validate.c +++ b/sound/usb/validate.c @@ -81,9 +81,9 @@ static bool validate_processing_unit(con switch (v->protocol) { case UAC_VERSION_1: default: - /* bNrChannels, wChannelConfig, iChannelNames, bControlSize */ - len += 1 + 2 + 1 + 1; - if (d->bLength < len) /* bControlSize */ + /* bNrChannels, wChannelConfig, iChannelNames */ + len += 1 + 2 + 1; + if (d->bLength < len + 1) /* bControlSize */ return false; m = hdr[len]; len += 1 + m + 1; /* bControlSize, bmControls, iProcessing */