ALSA: bcd2000: Fix a UAF bug on the error path of probing
authorZheyu Ma <zheyuma97@gmail.com>
Fri, 15 Jul 2022 01:05:15 +0000 (09:05 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 17 Aug 2022 12:22:46 +0000 (14:22 +0200)
commit64ca7f50ad96c2c65ae390b954925a36eabe04aa
treec7c80d716ab4b9f163f721b4b9f84c0e744386ce
parent30e8b553e0291fc9988a585f6ba8a71fdff7f050
ALSA: bcd2000: Fix a UAF bug on the error path of probing

commit ffb2759df7efbc00187bfd9d1072434a13a54139 upstream.

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: b47a22290d58 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sound/usb/bcd2000/bcd2000.c