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| author | Takashi Iwai <tiwai@suse.de> | 2017-10-04 15:03:40 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2017-10-11 15:14:49 +0200 |
| commit | 6815a0b444572527256f0d0efd8efe3ddede6018 (patch) | |
| tree | 4ce0bcd84bf6931a1e7e2d018b7c44580cde1e2d /sound/usb/bcd2000/bcd2000.c | |
| parent | e901b9873876ca30a09253731bd3a6b00c44b5b0 (diff) | |
| download | lwn-6815a0b444572527256f0d0efd8efe3ddede6018.tar.gz lwn-6815a0b444572527256f0d0efd8efe3ddede6018.zip | |
ALSA: bcd2000: Add a sanity check for invalid EPs
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>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb/bcd2000/bcd2000.c')
| -rw-r--r-- | sound/usb/bcd2000/bcd2000.c | 7 |
1 files changed, 7 insertions, 0 deletions
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; |