From: Takashi Iwai tiwai@suse.de
commit 0125de38122f0f66bf61336158d12a1aabfe6425 upstream.
At closing a USB MIDI output substream, there might be still a pending work, which would eventually access the rawmidi runtime object that is being released. For fixing the race, make sure to cancel the pending work at closing.
Reported-by: syzbot+6912c9592caca7ca0e7d@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/000000000000e7e75005dfd07cf6@google.com Link: https://lore.kernel.org/r/20220525131203.11299-1-tiwai@suse.de Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- sound/usb/midi.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/sound/usb/midi.c +++ b/sound/usb/midi.c @@ -1161,6 +1161,9 @@ static int snd_usbmidi_output_open(struc
static int snd_usbmidi_output_close(struct snd_rawmidi_substream *substream) { + struct usbmidi_out_port *port = substream->runtime->private_data; + + cancel_work_sync(&port->ep->work); return substream_open(substream, 0, 0); }