linux-stable.git/sound/drivers, branch v4.4.166

ALSA: aloop: Add missing cable lock to ctl API callbacks

2018-05-16T08:06:47+00:00

commit 76b3421b39bd610546931fc923edcf90c18fa395 upstream.

Some control API callbacks in aloop driver are too lazy to take the
loopback->cable_lock and it results in possible races of cable access
while it's being freed.  It eventually lead to a UAF, as reported by
fuzzer recently.

This patch covers such control API callbacks and add the proper mutex
locks.

Reported-by: DaeRyong Jeong 
Cc: 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: aloop: Mark paused device as inactive

2018-05-16T08:06:47+00:00

commit 306a4f3ca7f3c7dfa473ebd19d66e40e59d99734 upstream.

Show paused ALSA aloop device as inactive, i.e. the control
"PCM Slave Active" set as false. Notification sent upon state change.

This makes it possible for client capturing from aloop device to know if
data is expected. Without it the client expects data even if playback
is paused.

Signed-off-by: Robert Rosengren 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: opl3: Hardening for potential Spectre v1

2018-05-02T14:53:41+00:00

commit 7f054a5bee0987f1e2d4e59daea462421c76f2cb upstream.

As recently Smatch suggested, one place in OPL3 driver may expand the
array directly from the user-space value with speculation:
  sound/drivers/opl3/opl3_synth.c:476 snd_opl3_set_voice() warn: potential spectre issue 'snd_opl3_regmap'

This patch puts array_index_nospec() for hardening against it.

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

ALSA: aloop: Fix access to not-yet-ready substream via cable

2018-03-28T16:40:13+00:00

commit 8e6b1a72a75bb5067ccb6b56d8ca4aa3a300a64e upstream.

In loopback_open() and loopback_close(), we assign and release the
substream object to the corresponding cable in a racy way.  It's
neither locked nor done in the right position.  The open callback
assigns the substream before its preparation finishes, hence the other
side of the cable may pick it up, which may lead to the invalid memory
access.

This patch addresses these: move the assignment to the end of the open
callback, and wrap with cable->lock for avoiding concurrent accesses.

Cc: 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: aloop: Sync stale timer before release

2018-03-28T16:40:12+00:00

commit 67a01afaf3d34893cf7d2ea19b34555d6abb7cb0 upstream.

The aloop driver tries to stop the pending timer via timer_del() in
the trigger callback and in the close callback.  The former is
correct, as it's an atomic operation, while the latter expects that
the timer gets really removed and proceeds the resource releases after
that.  But timer_del() doesn't synchronize, hence the running timer
may still access the released resources.

A similar situation can be also seen in the prepare callback after
trigger(STOP) where the prepare tries to re-initialize the things
while a timer is still running.

The problems like the above are seen indirectly in some syzkaller
reports (although it's not 100% clear whether this is the only cause,
as the race condition is quite narrow and not always easy to
trigger).

For addressing these issues, this patch adds the explicit alls of
timer_del_sync() in some places, so that the pending timer is properly
killed / synced.

Cc: 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: aloop: Fix racy hw constraints adjustment

2018-01-17T08:35:26+00:00

commit 898dfe4687f460ba337a01c11549f87269a13fa2 upstream.

The aloop driver tries to update the hw constraints of the connected
target on the cable of the opened PCM substream.  This is done by
adding the extra hw constraints rules referring to the substream
runtime->hw fields, while the other substream may update the runtime
hw of another side on the fly.

This is, however, racy and may result in the inconsistent values when
both PCM streams perform the prepare concurrently.  One of the reason
is that it overwrites the other's runtime->hw field; which is not only
racy but also broken when it's called before the open of another side
finishes.  And, since the reference to runtime->hw isn't protected,
the concurrent write may give the partial value update and become
inconsistent.

This patch is an attempt to fix and clean up:
- The prepare doesn't change the runtime->hw of other side any longer,
  but only update the cable->hw that is referred commonly.
- The extra rules refer to the loopback_pcm object instead of the
  runtime->hw.  The actual hw is deduced from cable->hw.
- The extra rules take the cable_lock to protect against the race.

Fixes: b1c73fc8e697 ("ALSA: snd-aloop: Fix hw_params restrictions and checking")
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: aloop: Fix inconsistent format due to incomplete rule

2018-01-17T08:35:26+00:00

commit b088b53e20c7d09b5ab84c5688e609f478e5c417 upstream.

The extra hw constraint rule for the formats the aloop driver
introduced has a slight flaw, where it doesn't return a positive value
when the mask got changed.  It came from the fact that it's basically
a copy&paste from snd_hw_constraint_mask64().  The original code is
supposed to be a single-shot and it modifies the mask bits only once
and never after, while what we need for aloop is the dynamic hw rule
that limits the mask bits.

This difference results in the inconsistent state, as the hw_refine
doesn't apply the dependencies fully.  The worse and surprisingly
result is that it causes a crash in OSS emulation when multiple
full-duplex reads/writes are performed concurrently (I leave why it
triggers Oops to readers as a homework).

For fixing this, replace a few open-codes with the standard
snd_mask_*() macros.

Reported-by: syzbot+3902b5220e8ca27889ca@syzkaller.appspotmail.com
Fixes: b1c73fc8e697 ("ALSA: snd-aloop: Fix hw_params restrictions and checking")
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: aloop: Release cable upon open error path

2018-01-17T08:35:26+00:00

commit 9685347aa0a5c2869058ca6ab79fd8e93084a67f upstream.

The aloop runtime object and its assignment in the cable are left even
when opening a substream fails.  This doesn't mean any memory leak,
but it still keeps the invalid pointer that may be referred by the
another side of the cable spontaneously, which is a potential Oops
cause.

Clean up the cable assignment and the empty cable upon the error path
properly.

Fixes: 597603d615d2 ("ALSA: introduce the snd-aloop module for the PCM loopback")
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: vx: Fix possible transfer overflow

2017-11-21T08:21:20+00:00

[ Upstream commit 874e1f6fad9a5184b67f4cee37c1335cd2cc5677 ]

The pseudo DMA transfer codes in VX222 and VX-pocket driver have a
slight bug where they check the buffer boundary wrongly, and may
overflow.  Also, the zero sample count might be handled badly for the
playback (although it shouldn't happen in theory).  This patch
addresses these issues.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=141541
Signed-off-by: Takashi Iwai 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ALSA: vx: Don't try to update capture stream before running

2017-11-21T08:21:20+00:00

[ Upstream commit ed3c177d960bb5881b945ca6f784868126bb90db ]

The update of stream costs significantly, and we should avoid it
unless the stream really has started.  Check pipe->running flag
instead of pipe->prepared.

Signed-off-by: Takashi Iwai 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman