Commit c5aa956e authored Mar 09, 2021 by Pavel Skripkin Committed by Takashi Iwai Mar 09, 2021

ALSA: usb-audio: fix use after free in usb_audio_disconnect

The problem was in wrong "if" placement. chip->quirk_type is freed
in snd_card_free_when_closed(), but inside if statement it's accesed.

Fixes: 97991108 ("ALSA: usb-audio: Disable USB autosuspend properly in setup_disable_autosuspend()")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/16da19126ff461e5e64a9aec648cce28fb8ed73e.1615242183.git.paskripkin@gmail.com

Signed-off-by: Takashi Iwai <tiwai@suse.de>

parent 30dea071

sound/usb/card.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -907,6 +907,9 @@ static void usb_audio_disconnect(struct usb_interface *intf)
		}
		}

		if (chip->quirk_type & QUIRK_SETUP_DISABLE_AUTOSUSPEND)
		usb_enable_autosuspend(interface_to_usbdev(intf));

		chip->num_interfaces--;
		if (chip->num_interfaces <= 0) {
		usb_chip[chip->index] = NULL;
		@@ -915,9 +918,6 @@ static void usb_audio_disconnect(struct usb_interface *intf)
		} else {
		mutex_unlock(&register_mutex);
		}

		if (chip->quirk_type & QUIRK_SETUP_DISABLE_AUTOSUSPEND)
		usb_enable_autosuspend(interface_to_usbdev(intf));
		}

		/* lock the shutdown (disconnect) task and autoresume */