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@xxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
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;
--
2.14.2
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