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 4.3-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-4.3 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 5c06d68bc2a174a6b82dce9f100f55173b9a5189 Mon Sep 17 00:00:00 2001 From: Takashi Iwai <tiwai@xxxxxxx> Date: Tue, 12 Jan 2016 14:03:33 +0100 Subject: ALSA: usb-audio: Avoid calling usb_autopm_put_interface() at disconnect From: Takashi Iwai <tiwai@xxxxxxx> 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: [<ffffffff815ae7ef>] usb_autopm_put_interface+0xf/0x30 PGD 0 Call Trace: [<ffffffff8173bd94>] snd_usb_autosuspend+0x14/0x20 [<ffffffff817461bc>] snd_usb_pcm_close.isra.14+0x5c/0x90 [<ffffffff8174621f>] snd_usb_playback_close+0xf/0x20 [<ffffffff816ef58a>] snd_pcm_release_substream.part.36+0x3a/0x90 [<ffffffff816ef6b3>] snd_pcm_release+0xa3/0xb0 [<ffffffff816debb0>] snd_disconnect_release+0xd0/0xe0 [<ffffffff8114d417>] __fput+0x97/0x1d0 [<ffffffff8114d589>] ____fput+0x9/0x10 [<ffffffff8109e452>] task_work_run+0x72/0x90 [<ffffffff81088510>] do_exit+0x280/0xa80 [<ffffffff8108996a>] do_group_exit+0x3a/0xa0 [<ffffffff8109261f>] get_signal+0x1df/0x540 [<ffffffff81040903>] do_signal+0x23/0x620 [<ffffffff8114c128>] ? do_readv_writev+0x128/0x200 [<ffffffff810012e1>] prepare_exit_to_usermode+0x91/0xd0 [<ffffffff810013ba>] syscall_return_slowpath+0x9a/0x120 [<ffffffff817587cd>] ? __sys_recvmsg+0x5d/0x70 [<ffffffff810d2765>] ? ktime_get_ts64+0x45/0xe0 [<ffffffff8115dea0>] ? SyS_poll+0x60/0xf0 [<ffffffff818d2327>] 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 <tiwai@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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@xxxxxxx are queue-4.3/alsa-hrtimer-fix-stall-by-hrtimer_cancel.patch queue-4.3/alsa-hda-fix-white-noise-on-dell-latitude-e5550.patch queue-4.3/alsa-hda-fix-the-headset-mic-detection-problem-for-a-dell-laptop.patch queue-4.3/alsa-timer-harden-slave-timer-list-handling.patch queue-4.3/alsa-hda-fix-headphone-mic-input-on-a-few-dell-alc293-machines.patch queue-4.3/alsa-timer-fix-double-unlink-of-active_list.patch queue-4.3/alsa-hda-add-fixup-for-acer-aspire-one-cloudbook-14.patch queue-4.3/alsa-control-avoid-kernel-warnings-from-tlv-ioctl-with-numid-0.patch queue-4.3/alsa-hda-flush-the-pending-probe-work-at-remove.patch queue-4.3/alsa-hda-fixup-inverted-internal-mic-for-lenovo-e50-80.patch queue-4.3/alsa-usb-audio-add-sample-rate-inquiry-quirk-for-audioquest-dragonfly.patch queue-4.3/alsa-hda-realtek-dell-xps-one-alc3260-speaker-no-sound-after-resume-back.patch queue-4.3/alsa-hda-apply-hp-headphone-fixups-more-generically.patch queue-4.3/alsa-hda-set-codec-to-d3-at-reboot-shutdown-on-thinkpads.patch queue-4.3/alsa-hda-realtek-fix-silent-headphone-output-on-macpro-4-1-v2.patch queue-4.3/alsa-rme96-fix-unexpected-volume-reset-after-rate-changes.patch queue-4.3/alsa-fireworks-bebob-oxfw-dice-enable-to-make-as-built-in.patch queue-4.3/alsa-hda-set-skl-hda-controller-power-at-freeze-and-thaw.patch queue-4.3/alsa-hda-add-inverted-dmic-for-packard-bell-dots.patch queue-4.3/alsa-usb-add-native-dsd-support-for-oppo-ha-1.patch queue-4.3/alsa-hda-add-intel-lewisburg-device-ids-audio.patch queue-4.3/alsa-hda-add-keycode-map-for-alc-input-device.patch queue-4.3/alsa-hda-add-a-fixup-for-thinkpad-x1-carbon-2nd.patch queue-4.3/alsa-seq-fix-race-at-timer-setup-and-close.patch queue-4.3/alsa-hda-skip-eld-notification-during-system-suspend.patch queue-4.3/alsa-pcm-fix-snd_pcm_hw_params-struct-copy-in-compat-mode.patch queue-4.3/alsa-hda-add-mic-mute-hotkey-quirk-for-lenovo-thinkcentre-aio.patch queue-4.3/alsa-seq-fix-snd_seq_call_port_info_ioctl-in-compat-mode.patch queue-4.3/alsa-hda-disable-64bit-address-for-creative-hda-controllers.patch queue-4.3/alsa-hda-fix-noise-on-dell-latitude-e6440.patch queue-4.3/alsa-seq-fix-missing-null-check-at-remove_events-ioctl.patch queue-4.3/alsa-hda-ca0132-quirk-for-alienware-17-2015.patch queue-4.3/alsa-usb-audio-fix-mixer-ctl-regression-of-native-instrument-devices.patch queue-4.3/alsa-usb-audio-add-a-more-accurate-volume-quirk-for-audioquest-dragonfly.patch queue-4.3/alsa-hda-fix-headphone-noise-after-dell-xps-13-resume-back-from-s3.patch queue-4.3/alsa-hda-fix-noise-problems-on-thinkpad-t440s.patch queue-4.3/alsa-hda-fix-lost-4k-bdl-boundary-workaround.patch queue-4.3/alsa-timer-handle-disconnection-more-safely.patch queue-4.3/alsa-hda-fix-bass-pin-fixup-for-asus-n550jx.patch queue-4.3/alsa-timer-fix-race-among-timer-ioctls.patch queue-4.3/alsa-hda-apply-pin-fixup-for-hp-probook-6550b.patch queue-4.3/alsa-hda-fixing-speaker-noise-on-the-two-latest-thinkpad-models.patch queue-4.3/alsa-hda-add-fixup-for-dell-latitidue-e6540.patch queue-4.3/alsa-usb-audio-avoid-calling-usb_autopm_put_interface-at-disconnect.patch queue-4.3/alsa-hda-apply-click-noise-workaround-for-thinkpads-generically.patch queue-4.3/alsa-hda-fix-noise-on-gigabyte-z170x-mobo.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html