ALSA: usb-audio: More strict sanity checks for clock parsers (f5d76e9c) · Commits · 戴 / test

The sanity checks introduced for malformed descriptors loosely check the given descriptor size, although the size greater than the defined description is invalid. It was due to a concern of any funky firmware in the actual products. But this doesn't look hitting, and any sane products must have the defined descriptors. So in this patch, we make the validators more strict, allowing only with the defined descriptor sizes. The value in clock selector validator is corrected from 5 to 7 to count the two unlisted fields after baCSourceID[]. Suggested-by:

Ruslan Bilovol <ruslan.bilovol@gmail.com> Reviewed-by:

Ruslan Bilovol <ruslan.bilovol@gmail.com> Signed-off-by:

Takashi Iwai <tiwai@suse.de>

sound/usb/clock.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -52,7 +52,7 @@ static void find_uac_clock_desc(struct usb_host_interface iface, int id,
		static bool validate_clock_source_v2(void *p, int id)
		{
		struct uac_clock_source_descriptor *cs = p;
		return cs->bLength >= sizeof(*cs) && cs->bClockID == id;
		return cs->bLength == sizeof(*cs) && cs->bClockID == id;
		}

		static bool validate_clock_source_v3(void *p, int id)
		@@ -65,7 +65,7 @@ static bool validate_clock_selector_v2(void *p, int id)
		{
		struct uac_clock_selector_descriptor *cs = p;
		return cs->bLength >= sizeof(*cs) && cs->bClockID == id &&
		cs->bLength >= 5 + cs->bNrInPins;
		cs->bLength == 7 + cs->bNrInPins;
		}

		static bool validate_clock_selector_v3(void *p, int id)
		@@ -77,7 +77,7 @@ static bool validate_clock_selector_v3(void *p, int id)
		static bool validate_clock_multiplier_v2(void *p, int id)
		{
		struct uac_clock_multiplier_descriptor *cs = p;
		return cs->bLength >= sizeof(*cs) && cs->bClockID == id;
		return cs->bLength == sizeof(*cs) && cs->bClockID == id;
		}

		static bool validate_clock_multiplier_v3(void *p, int id)

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