From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757268Ab1KJEvv (ORCPT ); Wed, 9 Nov 2011 23:51:51 -0500 Received: from cantor2.suse.de ([195.135.220.15]:42996 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935398Ab1KJDcN (ORCPT ); Wed, 9 Nov 2011 22:32:13 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Wed Nov 9 13:27:20 2011 Message-Id: <20111109212720.112240800@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Wed, 09 Nov 2011 13:28:36 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Clemens Ladisch , Takashi Iwai Subject: [194/262] ALSA: ua101: fix crash when unplugging In-Reply-To: <20111109212847.GA20838@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Clemens Ladisch commit 862a6244eb9f9f5123fe819454fcfcae0ee1f2f9 upstream. If the device is unplugged while running, it is possible for a PCM device to be closed after the disconnect callback has returned. This means that kill_stream_urb() and disable_iso_interface() would try to access already-invalid or freed USB data structures. The function free_usb_related_resources() was intended to prevent this, but forgot to clear the affected variables. Reported-and-tested-by: Olivier Courtay Signed-off-by: Clemens Ladisch Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/usb/misc/ua101.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-) --- a/sound/usb/misc/ua101.c +++ b/sound/usb/misc/ua101.c @@ -459,7 +459,8 @@ static void kill_stream_urbs(struct ua10 unsigned int i; for (i = 0; i < stream->queue_length; ++i) - usb_kill_urb(&stream->urbs[i]->urb); + if (stream->urbs[i]) + usb_kill_urb(&stream->urbs[i]->urb); } static int enable_iso_interface(struct ua101 *ua, unsigned int intf_index) @@ -484,6 +485,9 @@ static void disable_iso_interface(struct { struct usb_host_interface *alts; + if (!ua->intf[intf_index]) + return; + alts = ua->intf[intf_index]->cur_altsetting; if (alts->desc.bAlternateSetting != 0) { int err = usb_set_interface(ua->dev, @@ -1144,27 +1148,37 @@ static void free_stream_urbs(struct ua10 { unsigned int i; - for (i = 0; i < stream->queue_length; ++i) + for (i = 0; i < stream->queue_length; ++i) { kfree(stream->urbs[i]); + stream->urbs[i] = NULL; + } } static void free_usb_related_resources(struct ua101 *ua, struct usb_interface *interface) { unsigned int i; + struct usb_interface *intf; + mutex_lock(&ua->mutex); free_stream_urbs(&ua->capture); free_stream_urbs(&ua->playback); + mutex_unlock(&ua->mutex); free_stream_buffers(ua, &ua->capture); free_stream_buffers(ua, &ua->playback); - for (i = 0; i < ARRAY_SIZE(ua->intf); ++i) - if (ua->intf[i]) { - usb_set_intfdata(ua->intf[i], NULL); - if (ua->intf[i] != interface) + for (i = 0; i < ARRAY_SIZE(ua->intf); ++i) { + mutex_lock(&ua->mutex); + intf = ua->intf[i]; + ua->intf[i] = NULL; + mutex_unlock(&ua->mutex); + if (intf) { + usb_set_intfdata(intf, NULL); + if (intf != interface) usb_driver_release_interface(&ua101_driver, - ua->intf[i]); + intf); } + } } static void ua101_card_free(struct snd_card *card)