When the driver fails in snd_card_register() at probe time, it will free
the 'bcd2k->midi_out_urb' before killing it, which may cause a UAF bug.
The following log can reveal it:
[ 50.727020] BUG: KASAN: use-after-free in bcd2000_input_complete+0x1f1/0x2e0 [snd_bcd2000]
[ 50.727623] Read of size 8 at addr ffff88810fab0e88 by task swapper/4/0
[ 50.729530] Call Trace:
[ 50.732899] bcd2000_input_complete+0x1f1/0x2e0 [snd_bcd2000]
Fix this by adding usb_kill_urb() before usb_free_urb().
Fixes: b47a22290d ("ALSA: MIDI driver for Behringer BCD2000 USB device")
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220715010515.2087925-1-zheyuma97@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
ffb2759df7