Commit 976a68f0 authored Nov 14, 2019 by Takashi Iwai

ALSA: usb-audio: Fix incorrect size check for processing/extension units

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: 57f87706 ("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>

parent cc9dbfa9

sound/usb/validate.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -81,9 +81,9 @@ static bool validate_processing_unit(const void *p,
		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 */

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