From: HyeongJun An Date: Wed, 1 Jul 2026 09:52:31 +0000 (+0900) Subject: ALSA: usx2y: us144mkii: fix work UAF on disconnect X-Git-Tag: v7.2-rc2~5^2~1 X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=147996e7e7c9e8339c0e04f6fa7ccb3e4d448ff7;p=thirdparty%2Fkernel%2Fstable.git ALSA: usx2y: us144mkii: fix work UAF on disconnect tascam_disconnect() cancels capture_work and midi_in_work before usb_kill_anchored_urbs() kills the capture/MIDI-in URBs. Those URBs self-resubmit, and their completion handlers reschedule the work. A URB that completes in the small window between cancel_work_sync() and usb_kill_anchored_urbs() therefore re-arms the work after its only cancel. Nothing cancels it again before snd_card_free() frees the card-private tascam structure, so the work handler then runs on freed memory. Kill the anchored URBs before cancelling the work; once the work is cancelled no remaining URB can complete to re-arm it. Fixes: c1bb0c13e430 ("ALSA: usb-audio: us144mkii: Implement audio capture and decoding") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-8 Signed-off-by: HyeongJun An Link: https://patch.msgid.link/20260701095231.1020811-1-sammiee5311@gmail.com Signed-off-by: Takashi Iwai --- diff --git a/sound/usb/usx2y/us144mkii.c b/sound/usb/usx2y/us144mkii.c index 94553b61013c..58ef23146f20 100644 --- a/sound/usb/usx2y/us144mkii.c +++ b/sound/usb/usx2y/us144mkii.c @@ -585,19 +585,24 @@ static void tascam_disconnect(struct usb_interface *intf) return; if (intf->cur_altsetting->desc.bInterfaceNumber == 0) { - /* Ensure all deferred work is complete before freeing resources */ snd_card_disconnect(tascam->card); - cancel_work_sync(&tascam->stop_work); - cancel_work_sync(&tascam->capture_work); - cancel_work_sync(&tascam->midi_in_work); - cancel_work_sync(&tascam->midi_out_work); - cancel_work_sync(&tascam->stop_pcm_work); + /* + * Kill the URBs before cancelling the work, so a late URB + * completion cannot re-arm a work that then runs after + * snd_card_free(). + */ usb_kill_anchored_urbs(&tascam->playback_anchor); usb_kill_anchored_urbs(&tascam->capture_anchor); usb_kill_anchored_urbs(&tascam->feedback_anchor); usb_kill_anchored_urbs(&tascam->midi_in_anchor); usb_kill_anchored_urbs(&tascam->midi_out_anchor); + + cancel_work_sync(&tascam->stop_work); + cancel_work_sync(&tascam->capture_work); + cancel_work_sync(&tascam->midi_in_work); + cancel_work_sync(&tascam->midi_out_work); + cancel_work_sync(&tascam->stop_pcm_work); timer_delete_sync(&tascam->error_timer); tascam_free_urbs(tascam); snd_card_free(tascam->card);