From: Takashi Iwai tiwai@suse.de
[ Upstream commit ff58bbc7b9704a5869204176f804eff57307fef0 ]
With the recent full-duplex support of implicit feedback streams, an endpoint can be still running after closing the capture stream as long as the playback stream with the sync-endpoint is running. In such a state, the URBs are still be handled and they may call retire_data_urb callback, which tries to transfer the data from the PCM buffer. Since the PCM stream gets closed, this may lead to use-after-free.
This patch adds the proper clearance of the callback at stopping the capture stream for addressing the possible UAF above.
Fixes: 10ce77e4817f ("ALSA: usb-audio: Add duplex sound support for USB devices using implicit feedback") Link: https://lore.kernel.org/r/20200616120921.12249-1-tiwai@suse.de Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- sound/usb/pcm.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index 6c391e5fad2a7..c36e6c97d09ae 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -1778,6 +1778,7 @@ static int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream return 0; case SNDRV_PCM_TRIGGER_STOP: stop_endpoints(subs, false); + subs->data_endpoint->retire_data_urb = NULL; subs->running = 0; return 0; case SNDRV_PCM_TRIGGER_PAUSE_PUSH: