linux_dsm_epyc7002/sound/core
Takashi Iwai e190161f96 ALSA: pcm: Fix tight loop of OSS capture stream
When the trigger=off is passed for a PCM OSS stream, it sets the
start_threshold of the given substream to the boundary size, so that
it won't be automatically started.  This can be problematic for a
capture stream, unfortunately, as detected by syzkaller.  The scenario
is like the following:

- In __snd_pcm_lib_xfer() that is invoked from snd_pcm_oss_read()
  loop, we have a check whether the stream was already started or the
  stream can be auto-started.
- The function at this check returns 0 with trigger=off since we
  explicitly disable the auto-start.
- The loop continues and repeats calling __snd_pcm_lib_xfer() tightly,
  which may lead to an RCU stall.

This patch fixes the bug by simply allowing the wait for non-started
stream in the case of OSS capture.  For native usages, it's supposed
to be done by the caller side (which is user-space), hence it returns
zero like before.

(In theory, __snd_pcm_lib_xfer() could wait even for the native API
 usage cases, too; but I'd like to stay in a safer side for not
 breaking the existing stuff for now.)

Reported-by: syzbot+fbe0496f92a0ce7b786c@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-01-25 19:45:46 +01:00
..
oss ALSA: oss: Use kvzalloc() for local buffer allocations 2018-11-09 14:12:04 +01:00
seq Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
compress_offload.c ALSA: compress: prevent potential divide by zero bugs 2019-01-03 16:32:57 +00:00
control_compat.c ALSA: control: fix a redundant-copy issue 2018-05-13 09:27:57 +02:00
control.c ALSA: control: Consolidate helpers for adding and replacing ctl elements 2018-11-24 20:04:10 +01:00
ctljack.c ALSA: declare snd_kcontrol_new structures as const 2017-05-30 10:29:25 +02:00
device.c ALSA: core: Assure control device to be registered at last 2018-05-17 08:21:23 +02:00
hrtimer.c Merge branch 'for-next' into for-linus 2017-11-13 15:43:13 +01:00
hwdep_compat.c
hwdep.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-01-31 09:25:20 -08:00
info_oss.c ALSA: core: Follow standard EXPORT_SYMBOL() declarations 2017-06-16 16:19:16 +02:00
info.c sound: Use octal not symbolic permissions 2018-05-28 11:27:20 +02:00
init.c sound: Use octal not symbolic permissions 2018-05-28 11:27:20 +02:00
isadma.c ALSA: core: Follow standard EXPORT_SYMBOL() declarations 2017-06-16 16:19:16 +02:00
jack.c ALSA: fix kernel-doc build warning 2017-10-30 08:10:07 +01:00
Kconfig docs: Fix some broken references 2018-06-15 18:10:01 -03:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
memalloc.c ALSA: memalloc: Add fall-through annotation 2018-10-12 09:31:23 +02:00
memory.c ALSA: core: Follow standard EXPORT_SYMBOL() declarations 2017-06-16 16:19:16 +02:00
misc.c ALSA: core: Follow standard EXPORT_SYMBOL() declarations 2017-06-16 16:19:16 +02:00
pcm_compat.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
pcm_dmaengine.c ASoC: dmaengine_pcm: Add support for packed transfers 2016-04-27 17:34:11 +01:00
pcm_drm_eld.c ALSA: pcm: use helper function to refer parameter as read-only 2017-05-17 07:24:39 +02:00
pcm_iec958.c ALSA: pcm: Allow 32 bit sample format in IEC958 channel status helper 2016-04-06 14:33:38 -07:00
pcm_lib.c ALSA: pcm: Fix tight loop of OSS capture stream 2019-01-25 19:45:46 +01:00
pcm_local.h ALSA: pcm: trace XRUN event at injection, too 2018-07-04 15:34:57 +02:00
pcm_memory.c sound: Use octal not symbolic permissions 2018-05-28 11:27:20 +02:00
pcm_misc.c ALSA: pcm: add SNDRV_PCM_FORMAT_{S,U}20 2017-11-29 09:26:33 +01:00
pcm_native.c ALSA: pcm: Fix starvation on down_write_nonblock() 2018-11-29 08:15:19 +01:00
pcm_param_trace.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pcm_timer.c ALSA: pcm: include pcm_local.h and remove some extraneous tabs 2017-05-30 18:04:47 +02:00
pcm_trace.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pcm.c ALSA: pcm: Fix potential Spectre v1 vulnerability 2018-12-13 09:14:33 +01:00
rawmidi_compat.c ALSA: rawmidi: Fix missing input substream checks in compat ioctls 2018-04-19 18:16:15 +02:00
rawmidi.c ALSA: rawmidi: A lightweight function to discard pending bytes 2018-10-04 20:13:17 +02:00
seq_device.c ALSA: seq: Cancel pending autoload work at unbinding device 2017-09-12 12:41:20 +02:00
sgbuf.c ALSA: memalloc: Add non-cached buffer type 2018-08-28 13:56:47 +02:00
sound_oss.c ALSA: core: Follow standard EXPORT_SYMBOL() declarations 2017-06-16 16:19:16 +02:00
sound.c ALSA: core: Follow standard EXPORT_SYMBOL() declarations 2017-06-16 16:19:16 +02:00
timer_compat.c ALSA: timer: Remove kernel warning at compat ioctl error paths 2017-11-21 16:36:11 +01:00
timer.c ALSA: timer: catch invalid timer object creation 2018-07-22 10:42:41 +02:00
vmaster.c - Introduce arithmetic overflow test helper functions (Rasmus) 2018-06-06 17:27:14 -07:00