Commit 48bd344e authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman Committed by Takashi Iwai
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ALSA: usx2y: us144mkii: fix NULL deref on missing interface 0 



A malicious USB device with the TASCAM US-144MKII device id can have a
configuration containing bInterfaceNumber=1 but no interface 0.  USB
configuration descriptors are not required to assign interface numbers
sequentially, so usb_ifnum_to_if(dev, 0) returns will NULL, which will
then be dereferenced directly.

Fix this up by checking the return value properly.

Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Fixes: dee1bcf2 ("ALSA: usb-audio: Add initial driver for TASCAM US-144MKII")
Cc: stable <stable@kernel.org>
Assisted-by: gregkh_clanker_t1000
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/2026040955-fall-gaining-e338@gregkh


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 01f218d4

sound/usb/usx2y/us144mkii.c

+5 −1
Original line number Diff line number Diff line
@@ -420,7 +420,11 @@ static int tascam_probe(struct usb_interface *intf, 


	/* The device has two interfaces; we drive both from this driver. */

	if (intf->cur_altsetting->desc.bInterfaceNumber == 1) {

		tascam = usb_get_intfdata(usb_ifnum_to_if(dev, 0));

		struct usb_interface *intf_zero = usb_ifnum_to_if(dev, 0);



		if (!intf_zero)

			return -ENODEV;

		tascam = usb_get_intfdata(intf_zero);

		if (tascam) {

			usb_set_intfdata(intf, tascam);

			tascam->iface1 = intf;