Patch "ALSA: bcd2000: Add a sanity check for invalid EPs" has been added to the 4.14-stable tree

This is a note to let you know that I've just added the patch titled

ALSA: bcd2000: Add a sanity check for invalid EPs

to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
alsa-bcd2000-add-a-sanity-check-for-invalid-eps.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Takashi Iwai <[email protected]>
Date: Wed, 4 Oct 2017 15:03:40 +0200
Subject: ALSA: bcd2000: Add a sanity check for invalid EPs

From: Takashi Iwai <[email protected]>

commit 6815a0b444572527256f0d0efd8efe3ddede6018 upstream.

As syzkaller spotted, currently bcd2000 driver submits a URB with the fixed EP without checking whether it's actually available, which may result in a kernel warning like:
usb 1-1: BOGUS urb xfer, pipe 1 != type 3

  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 1846 at drivers/usb/core/urb.c:449
  usb_submit_urb+0xf8a/0x11d0
  Modules linked in:
  CPU: 0 PID: 1846 Comm: kworker/0:2 Not tainted
  4.14.0-rc2-42613-g1488251d1a98 #238
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
  Workqueue: usb_hub_wq hub_event
  Call Trace:
   bcd2000_init_device sound/usb/bcd2000/bcd2000.c:289
   bcd2000_init_midi sound/usb/bcd2000/bcd2000.c:345
   bcd2000_probe+0xe64/0x19e0 sound/usb/bcd2000/bcd2000.c:406
   usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361
   ....

This patch adds a sanity check of validity of EPs at the device initialization phase for avoiding the call with an invalid EP.

---
 sound/usb/bcd2000/bcd2000.c |    7 +++++++
 1 file changed, 7 insertions(+)

@@ -342,6 +342,13 @@ static int bcd2000_init_midi(struct bcd2
 				bcd2k->midi_out_buf, BUFSIZE,
 				bcd2000_output_complete, bcd2k, 1);
 
+	/* sanity checks of EPs before actually submitting */
+	if (usb_urb_ep_type_check(bcd2k->midi_in_urb) ||
+	    usb_urb_ep_type_check(bcd2k->midi_out_urb)) {
+		dev_err(&bcd2k->dev->dev, "invalid MIDI EP\n");
+		return -EINVAL;
+	}
+
 	bcd2000_init_device(bcd2k);
 
 	return 0;

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/alsa-bcd2000-add-a-sanity-check-for-invalid-eps.patch queue-4.14/alsa-caiaq-add-a-sanity-check-for-invalid-eps.patch queue-4.14/alsa-line6-add-a-sanity-check-for-invalid-eps.patch queue-4.14/usb-core-add-a-helper-function-to-check-the-validity-of-ep-type-in-urb.patch