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.
Reported-by: Andrey Konovalov andreyknvl@google.com Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/usb/bcd2000/bcd2000.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/sound/usb/bcd2000/bcd2000.c b/sound/usb/bcd2000/bcd2000.c index 7371e5b06035..a6408209d7f1 100644 --- a/sound/usb/bcd2000/bcd2000.c +++ b/sound/usb/bcd2000/bcd2000.c @@ -342,6 +342,13 @@ static int bcd2000_init_midi(struct bcd2000 *bcd2k) 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;