Commit d5002436 authored Apr 05, 2022 by Borislav Petkov Committed by Greg Kroah-Hartman Apr 27, 2022

ALSA: usb-audio: Fix undefined behavior due to shift overflowing the constant

[ Upstream commit 1ef8715975de8bd481abbd0839ed4f49d9e5b0ff ]

Fix:

  sound/usb/midi.c: In function ‘snd_usbmidi_out_endpoint_create’:
  sound/usb/midi.c:1389:2: error: case label does not reduce to an integer constant
    case USB_ID(0xfc08, 0x0101): /* Unknown vendor Cable */
    ^~~~

See https://lore.kernel.org/r/YkwQ6%2BtIH8GQpuct@zn.tnic

 for the gory
details as to why it triggers with older gccs only.

[ A slight correction with parentheses around the argument by tiwai ]

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220405151517.29753-3-bp@alien8.de


Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent c4c4ff82

sound/usb/usbaudio.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -22,7 +22,7 @@
		*/

		/* handling of USB vendor/product ID pairs as 32-bit numbers */
		#define USB_ID(vendor, product) (((vendor) << 16) \| (product))
		#define USB_ID(vendor, product) (((unsigned int)(vendor) << 16) \| (product))
		#define USB_ID_VENDOR(id) ((id) >> 16)
		#define USB_ID_PRODUCT(id) ((u16)(id))