This is a note to let you know that I've just added the patch titled
ALSA: timer: Remove kernel warning at compat ioctl error paths
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: alsa-timer-remove-kernel-warning-at-compat-ioctl-error-paths.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 3d4e8303f2c747c8540a0a0126d0151514f6468b Mon Sep 17 00:00:00 2001
From: Takashi Iwai tiwai@suse.de Date: Tue, 21 Nov 2017 16:36:11 +0100 Subject: ALSA: timer: Remove kernel warning at compat ioctl error paths
From: Takashi Iwai tiwai@suse.de
commit 3d4e8303f2c747c8540a0a0126d0151514f6468b upstream.
Some timer compat ioctls have NULL checks of timer instance with snd_BUG_ON() that bring up WARN_ON() when the debug option is set. Actually the condition can be met in the normal situation and it's confusing and bad to spew kernel warnings with stack trace there. Let's remove snd_BUG_ON() invocation and replace with the simple checks. Also, correct the error code to EBADFD to follow the native ioctl error handling.
Reported-by: syzbot syzkaller@googlegroups.com Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- sound/core/timer_compat.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
--- a/sound/core/timer_compat.c +++ b/sound/core/timer_compat.c @@ -66,11 +66,11 @@ static int snd_timer_user_info_compat(st struct snd_timer *t;
tu = file->private_data; - if (snd_BUG_ON(!tu->timeri)) - return -ENXIO; + if (!tu->timeri) + return -EBADFD; t = tu->timeri->timer; - if (snd_BUG_ON(!t)) - return -ENXIO; + if (!t) + return -EBADFD; memset(&info, 0, sizeof(info)); info.card = t->card ? t->card->number : -1; if (t->hw.flags & SNDRV_TIMER_HW_SLAVE) @@ -99,8 +99,8 @@ static int snd_timer_user_status_compat( struct snd_timer_status32 status; tu = file->private_data; - if (snd_BUG_ON(!tu->timeri)) - return -ENXIO; + if (!tu->timeri) + return -EBADFD; memset(&status, 0, sizeof(status)); status.tstamp.tv_sec = tu->tstamp.tv_sec; status.tstamp.tv_nsec = tu->tstamp.tv_nsec;
Patches currently in stable-queue which might be from tiwai@suse.de are
queue-4.9/alsa-usb-audio-fix-potential-zero-division-at-parsing-fu.patch queue-4.9/alsa-timer-remove-kernel-warning-at-compat-ioctl-error-paths.patch queue-4.9/alsa-hda-add-raven-pci-id.patch queue-4.9/alsa-usb-audio-add-sanity-checks-in-v2-clock-parsers.patch queue-4.9/alsa-hda-fix-too-short-hdmi-dp-chmap-reporting.patch queue-4.9/alsa-hda-realtek-fix-alc700-family-no-sound-issue.patch queue-4.9/alsa-usb-audio-fix-potential-out-of-bound-access-at-parsing-su.patch queue-4.9/alsa-pcm-update-tstamp-only-if-audio_tstamp-changed.patch queue-4.9/alsa-usb-audio-add-sanity-checks-to-fe-parser.patch