From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:47126 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932606AbcAZAix (ORCPT ); Mon, 25 Jan 2016 19:38:53 -0500 Subject: Patch "ALSA: usb-audio: Avoid calling usb_autopm_put_interface() at disconnect" has been added to the 4.4-stable tree To: tiwai@suse.de, gregkh@linuxfoundation.org Cc: , From: Date: Mon, 25 Jan 2016 16:38:52 -0800 Message-ID: <145376873290214@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled ALSA: usb-audio: Avoid calling usb_autopm_put_interface() at disconnect to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: alsa-usb-audio-avoid-calling-usb_autopm_put_interface-at-disconnect.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 5c06d68bc2a174a6b82dce9f100f55173b9a5189 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 12 Jan 2016 14:03:33 +0100 Subject: ALSA: usb-audio: Avoid calling usb_autopm_put_interface() at disconnect From: Takashi Iwai commit 5c06d68bc2a174a6b82dce9f100f55173b9a5189 upstream. ALSA PCM may still have a leftover instance after disconnection and it delays its release. The problem is that the PCM close code path of USB-audio driver has a call of snd_usb_autosuspend(). This involves with the call of usb_autopm_put_interface() and it may lead to a kernel Oops due to the NULL object like: BUG: unable to handle kernel NULL pointer dereference at 0000000000000190 IP: [] usb_autopm_put_interface+0xf/0x30 PGD 0 Call Trace: [] snd_usb_autosuspend+0x14/0x20 [] snd_usb_pcm_close.isra.14+0x5c/0x90 [] snd_usb_playback_close+0xf/0x20 [] snd_pcm_release_substream.part.36+0x3a/0x90 [] snd_pcm_release+0xa3/0xb0 [] snd_disconnect_release+0xd0/0xe0 [] __fput+0x97/0x1d0 [] ____fput+0x9/0x10 [] task_work_run+0x72/0x90 [] do_exit+0x280/0xa80 [] do_group_exit+0x3a/0xa0 [] get_signal+0x1df/0x540 [] do_signal+0x23/0x620 [] ? do_readv_writev+0x128/0x200 [] prepare_exit_to_usermode+0x91/0xd0 [] syscall_return_slowpath+0x9a/0x120 [] ? __sys_recvmsg+0x5d/0x70 [] ? ktime_get_ts64+0x45/0xe0 [] ? SyS_poll+0x60/0xf0 [] int_ret_from_sys_call+0x25/0x8f We have already a check of disconnection in snd_usb_autoresume(), but the check is missing its counterpart. The fix is just to put the same check in snd_usb_autosuspend(), too. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=109431 Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/usb/card.c | 2 ++ 1 file changed, 2 insertions(+) --- a/sound/usb/card.c +++ b/sound/usb/card.c @@ -675,6 +675,8 @@ int snd_usb_autoresume(struct snd_usb_au void snd_usb_autosuspend(struct snd_usb_audio *chip) { + if (atomic_read(&chip->shutdown)) + return; if (atomic_dec_and_test(&chip->active)) usb_autopm_put_interface(chip->pm_intf); } Patches currently in stable-queue which might be from tiwai@suse.de are queue-4.4/alsa-hrtimer-fix-stall-by-hrtimer_cancel.patch queue-4.4/alsa-hda-fix-white-noise-on-dell-latitude-e5550.patch queue-4.4/alsa-hda-fix-the-headset-mic-detection-problem-for-a-dell-laptop.patch queue-4.4/alsa-timer-harden-slave-timer-list-handling.patch queue-4.4/alsa-timer-fix-double-unlink-of-active_list.patch queue-4.4/alsa-control-avoid-kernel-warnings-from-tlv-ioctl-with-numid-0.patch queue-4.4/alsa-hda-flush-the-pending-probe-work-at-remove.patch queue-4.4/alsa-hda-fixup-inverted-internal-mic-for-lenovo-e50-80.patch queue-4.4/alsa-usb-add-native-dsd-support-for-oppo-ha-1.patch queue-4.4/alsa-hda-fix-missing-module-loading-with-model-generic-option.patch queue-4.4/alsa-seq-fix-race-at-timer-setup-and-close.patch queue-4.4/alsa-pcm-fix-snd_pcm_hw_params-struct-copy-in-compat-mode.patch queue-4.4/alsa-seq-fix-snd_seq_call_port_info_ioctl-in-compat-mode.patch queue-4.4/alsa-seq-fix-missing-null-check-at-remove_events-ioctl.patch queue-4.4/alsa-usb-audio-fix-mixer-ctl-regression-of-native-instrument-devices.patch queue-4.4/alsa-timer-handle-disconnection-more-safely.patch queue-4.4/alsa-hda-fix-bass-pin-fixup-for-asus-n550jx.patch queue-4.4/alsa-timer-fix-race-among-timer-ioctls.patch queue-4.4/alsa-hda-add-fixup-for-dell-latitidue-e6540.patch queue-4.4/alsa-usb-audio-avoid-calling-usb_autopm_put_interface-at-disconnect.patch