linux-toradex.git/sound/core, branch v4.17

ALSA: timer: Fix pause event notification

2018-05-18T06:43:59+00:00

Commit f65e0d299807 ("ALSA: timer: Call notifier in the same spinlock")
combined the start/continue and stop/pause functions, and in doing so
changed the event code for the pause case to SNDRV_TIMER_EVENT_CONTINUE.
Change it back to SNDRV_TIMER_EVENT_PAUSE.

Fixes: f65e0d299807 ("ALSA: timer: Call notifier in the same spinlock")
Signed-off-by: Ben Hutchings 
Cc: stable@vger.kernel.org
Signed-off-by: Takashi Iwai

ALSA: control: fix a redundant-copy issue

2018-05-13T07:27:57+00:00

In snd_ctl_elem_add_compat(), the fields of the struct 'data' need to be
copied from the corresponding fields of the struct 'data32' in userspace.
This is achieved by invoking copy_from_user() and get_user() functions. The
problem here is that the 'type' field is copied twice. One is by
copy_from_user() and one is by get_user(). Given that the 'type' field is
not used between the two copies, the second copy is *completely* redundant
and should be removed for better performance and cleanup. Also, these two
copies can cause inconsistent data: as the struct 'data32' resides in
userspace and a malicious userspace process can race to change the 'type'
field between the two copies to cause inconsistent data. Depending on how
the data is used in the future, such an inconsistency may cause potential
security risks.

For above reasons, we should take out the second copy.

Signed-off-by: Wenwen Wang 
Cc: 
Signed-off-by: Takashi Iwai

ALSA: pcm: Check PCM state at xfern compat ioctl

2018-05-02T06:54:54+00:00

Since snd_pcm_ioctl_xfern_compat() has no PCM state check, it may go
further and hit the sanity check pcm_sanity_check() when the ioctl is
called right after open.  It may eventually spew a kernel warning, as
triggered by syzbot, depending on kconfig.

The lack of PCM state check there was just an oversight.  Although
it's no real crash, the spurious kernel warning is annoying, so let's
add the proper check.

Reported-by: syzbot+1dac3a4f6bc9c1c675d4@syzkaller.appspotmail.com
Cc: 
Signed-off-by: Takashi Iwai

ALSA: seq: Fix races at MIDI encoding in snd_virmidi_output_trigger()

2018-04-27T15:50:37+00:00

The sequencer virmidi code has an open race at its output trigger
callback: namely, virmidi keeps only one event packet for processing
while it doesn't protect for concurrent output trigger calls.

snd_virmidi_output_trigger() tries to process the previously
unfinished event before starting encoding the given MIDI stream, but
this is done without any lock.  Meanwhile, if another rawmidi stream
starts the output trigger, this proceeds further, and overwrites the
event package that is being processed in another thread.  This
eventually corrupts and may lead to the invalid memory access if the
event type is like SYSEX.

The fix is just to move the spinlock to cover both the pending event
and the new stream.

The bug was spotted by a new fuzzer, RaceFuzzer.

BugLink: http://lkml.kernel.org/r/20180426045223.GA15307@dragonet.kaist.ac.kr
Reported-by: DaeRyong Jeong 
Cc: 
Signed-off-by: Takashi Iwai

ALSA: seq: oss: Hardening for potential Spectre v1

2018-04-25T08:37:45+00:00

As Smatch recently suggested, a few places in OSS sequencer codes may
expand the array directly from the user-space value with speculation,
namely there are a significant amount of references to either
info->ch[] or dp->synths[] array:

  sound/core/seq/oss/seq_oss_event.c:315 note_on_event() warn: potential spectre issue 'info->ch' (local cap)
  sound/core/seq/oss/seq_oss_event.c:362 note_off_event() warn: potential spectre issue 'info->ch' (local cap)
  sound/core/seq/oss/seq_oss_synth.c:470 snd_seq_oss_synth_load_patch() warn: potential spectre issue 'dp->synths' (local cap)
  sound/core/seq/oss/seq_oss_event.c:293 note_on_event() warn: potential spectre issue 'dp->synths'
  sound/core/seq/oss/seq_oss_event.c:353 note_off_event() warn: potential spectre issue 'dp->synths'
  sound/core/seq/oss/seq_oss_synth.c:506 snd_seq_oss_synth_sysex() warn: potential spectre issue 'dp->synths'
  sound/core/seq/oss/seq_oss_synth.c:580 snd_seq_oss_synth_ioctl() warn: potential spectre issue 'dp->synths'

Although all these seem doing only the first load without further
reference, we may want to stay in a safer side, so hardening with
array_index_nospec() would still make sense.

We may put array_index_nospec() at each place, but here we take a
different approach:

- For dp->synths[], change the helpers to retrieve seq_oss_synthinfo
  pointer directly instead of the array expansion at each place

- For info->ch[], harden in a normal way, as there are only a couple
  of places

As a result, the existing helper, snd_seq_oss_synth_is_valid() is
replaced with snd_seq_oss_synth_info().  Also, we cover MIDI device
where a similar array expansion is done, too, although it wasn't
reported by Smatch.

BugLink: https://marc.info/?l=linux-kernel&m=152411496503418&w=2
Reported-by: Dan Carpenter 
Cc: 
Signed-off-by: Takashi Iwai

ALSA: seq: oss: Fix unbalanced use lock for synth MIDI device

2018-04-25T08:37:45+00:00

When get_synthdev() is called for a MIDI device, it returns the fixed
midi_synth_dev without the use refcounting.  OTOH, the caller is
supposed to unreference unconditionally after the usage, so this would
lead to unbalanced refcount.

This patch corrects the behavior and keep up the refcount balance also
for the MIDI synth device.

Cc: 
Signed-off-by: Takashi Iwai

ALSA: pcm: Change return type to vm_fault_t

2018-04-25T06:15:45+00:00

Use new return type vm_fault_t for fault handler. For
now, this is just documenting that the function returns
a VM_FAULT value rather than an errno. Once all instances
are converted, vm_fault_t will become a distinct type.

Commit 1c8f422059ae ("mm: change return type to vm_fault_t")

Signed-off-by: Souptick Joarder 
Reviewed-by: Matthew Wilcox 
Signed-off-by: Takashi Iwai

ALSA: control: Fix missing __user annotation

2018-04-23T14:19:52+00:00

There is one place missing __user annotation to the pointer used by
the recent code refactoring.  Reported by sparse.

Fixes: 450296f305f1 ("ALSA: control: code refactoring TLV ioctl handler")
Reviewed-by: Takashi Sakamoto 
Signed-off-by: Takashi Iwai

ALSA: core: Report audio_tstamp in snd_pcm_sync_ptr

2018-04-23T06:47:03+00:00

It looks like a simple mistake that this struct member
was forgotten.

Audio_tstamp isn't used much, and on some archs (such as x86) this
ioctl is not used by default, so that might be the reason why this
has slipped for so long.

Fixes: 4eeaaeaea1ce ("ALSA: core: add hooks for audio timestamps")
Signed-off-by: David Henningsson 
Reviewed-by: Takashi Sakamoto 
Cc:  # v3.8+
Signed-off-by: Takashi Iwai

ALSA: pcm: Return negative delays from SNDRV_PCM_IOCTL_DELAY.

2018-04-23T06:41:35+00:00

The commit c2c86a97175f ("ALSA: pcm: Remove set_fs() in PCM core code")
changed SNDRV_PCM_IOCTL_DELAY to return an inconsistent error instead of a
negative delay.  Originally the call would succeed and return the negative
delay.  The Chromium OS Audio Server (CRAS) gets confused and hangs when
the error is returned instead of the negative delay.

Help CRAS avoid the issue by rolling back the behavior to return a
negative delay instead of an error.

Fixes: c2c86a97175f ("ALSA: pcm: Remove set_fs() in PCM core code")
Signed-off-by: Jeffery Miller 
Cc:  # v4.13+
Signed-off-by: Takashi Iwai