linux.git/sound/core/oss, branch v4.14.207

ALSA: pcm: oss: Remove superfluous WARN_ON() for mulaw sanity check

2020-09-09T17:03:11+00:00

commit 949a1ebe8cea7b342085cb6a4946b498306b9493 upstream.

The PCM OSS mulaw plugin has a check of the format of the counter part
whether it's a linear format.  The check is with snd_BUG_ON() that
emits WARN_ON() when the debug config is set, and it confuses
syzkaller as if it were a serious issue.  Let's drop snd_BUG_ON() for
avoiding that.

While we're at it, correct the error code to a more suitable, EINVAL.

Reported-by: syzbot+23b22dc2e0b81cbfcc95@syzkaller.appspotmail.com
Cc: 
Link: https://lore.kernel.org/r/20200901131802.18157-1-tiwai@suse.de
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: pcm: oss: Place the plugin buffer overflow checks correctly

2020-05-05T17:15:50+00:00

commit 4285de0725b1bf73608abbcd35ad7fd3ddc0b61e upstream.

The checks of the plugin buffer overflow in the previous fix by commit
  f2ecf903ef06 ("ALSA: pcm: oss: Avoid plugin buffer overflow")
are put in the wrong places mistakenly, which leads to the expected
(repeated) sound when the rate plugin is involved.  Fix in the right
places.

Also, at those right places, the zero check is needed for the
termination node, so added there as well, and let's get it done,
finally.

Fixes: f2ecf903ef06 ("ALSA: pcm: oss: Avoid plugin buffer overflow")
Cc: 
Link: https://lore.kernel.org/r/20200424193350.19678-1-tiwai@suse.de
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: pcm: oss: Fix regression by buffer overflow fix

2020-04-24T06:00:35+00:00

commit ae769d3556644888c964635179ef192995f40793 upstream.

The recent fix for the OOB access in PCM OSS plugins (commit
f2ecf903ef06: "ALSA: pcm: oss: Avoid plugin buffer overflow") caused a
regression on OSS applications.  The patch introduced the size check
in client and slave size calculations to limit to each plugin's buffer
size, but I overlooked that some code paths call those without
allocating the buffer but just for estimation.

This patch fixes the bug by skipping the size check for those code
paths while keeping checking in the actual transfer calls.

Fixes: f2ecf903ef06 ("ALSA: pcm: oss: Avoid plugin buffer overflow")
Tested-and-reported-by: Jari Ruusu 
Cc: 
Link: https://lore.kernel.org/r/20200403072515.25539-1-tiwai@suse.de
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: pcm: oss: Remove WARNING from snd_pcm_plug_alloc() checks

2020-04-02T14:34:17+00:00

commit 5461e0530c222129dfc941058be114b5cbc00837 upstream.

The return value checks in snd_pcm_plug_alloc() are covered with
snd_BUG_ON() macro that may trigger a kernel WARNING depending on the
kconfig.  But since the error condition can be triggered by a weird
user space parameter passed to OSS layer, we shouldn't give the kernel
stack trace just for that.  As it's a normal error condition, let's
remove snd_BUG_ON() macro usage there.

Reported-by: syzbot+2a59ee7a9831b264f45e@syzkaller.appspotmail.com
Cc: 
Link: https://lore.kernel.org/r/20200312155730.7520-1-tiwai@suse.de
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: pcm: oss: Avoid plugin buffer overflow

2020-04-02T14:34:17+00:00

commit f2ecf903ef06eb1bbbfa969db9889643d487e73a upstream.

Each OSS PCM plugins allocate its internal buffer per pre-calculation
of the max buffer size through the chain of plugins (calling
src_frames and dst_frames callbacks).  This works for most plugins,
but the rate plugin might behave incorrectly.  The calculation in the
rate plugin involves with the fractional position, i.e. it may vary
depending on the input position.  Since the buffer size
pre-calculation is always done with the offset zero, it may return a
shorter size than it might be; this may result in the out-of-bound
access as spotted by fuzzer.

This patch addresses those possible buffer overflow accesses by simply
setting the upper limit per the given buffer size for each plugin
before src_frames() and after dst_frames() calls.

Reported-by: syzbot+e1fe9f44fb8ecf4fb5dd@syzkaller.appspotmail.com
Cc: 
Link: https://lore.kernel.org/r/000000000000b25ea005a02bcf21@google.com
Link: https://lore.kernel.org/r/20200309082148.19855-1-tiwai@suse.de
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: pcm: oss: Avoid potential buffer overflows

2019-12-17T19:38:45+00:00

commit 4cc8d6505ab82db3357613d36e6c58a297f57f7c upstream.

syzkaller reported an invalid access in PCM OSS read, and this seems
to be an overflow of the internal buffer allocated for a plugin.
Since the rate plugin adjusts its transfer size dynamically, the
calculation for the chained plugin might be bigger than the given
buffer size in some extreme cases, which lead to such an buffer
overflow as caught by KASAN.

Fix it by limiting the max transfer size properly by checking against
the destination size in each plugin transfer callback.

Reported-by: syzbot+f153bde47a62e0b05f83@syzkaller.appspotmail.com
Cc: 
Link: https://lore.kernel.org/r/20191204144824.17801-1-tiwai@suse.de
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: pcm: signedness bug in snd_pcm_plug_alloc()

2019-11-20T16:59:37+00:00

[ Upstream commit 6f128fa41f310e1f39ebcea9621d2905549ecf52 ]

The "frames" variable is unsigned so the error handling doesn't work
properly.

Signed-off-by: Dan Carpenter 
Signed-off-by: Takashi Iwai 
Signed-off-by: Sasha Levin

ALSA: pcm: Fix possible OOB access in PCM oss plugins

2019-04-03T04:25:16+00:00

commit ca0214ee2802dd47239a4e39fb21c5b00ef61b22 upstream.

The PCM OSS emulation converts and transfers the data on the fly via
"plugins".  The data is converted over the dynamically allocated
buffer for each plugin, and recently syzkaller caught OOB in this
flow.

Although the bisection by syzbot pointed out to the commit
65766ee0bf7f ("ALSA: oss: Use kvzalloc() for local buffer
allocations"), this is merely a commit to replace vmalloc() with
kvmalloc(), hence it can't be the cause.  The further debug action
revealed that this happens in the case where a slave PCM doesn't
support only the stereo channels while the OSS stream is set up for a
mono channel.  Below is a brief explanation:

At each OSS parameter change, the driver sets up the PCM hw_params
again in snd_pcm_oss_change_params_lock().  This is also the place
where plugins are created and local buffers are allocated.  The
problem is that the plugins are created before the final hw_params is
determined.  Namely, two snd_pcm_hw_param_near() calls for setting the
period size and periods may influence on the final result of channels,
rates, etc, too, while the current code has already created plugins
beforehand with the premature values.  So, the plugin believes that
channels=1, while the actual I/O is with channels=2, which makes the
driver reading/writing over the allocated buffer size.

The fix is simply to move the plugin allocation code after the final
hw_params call.

Reported-by: syzbot+d4503ae45b65c5bc1194@syzkaller.appspotmail.com
Cc: 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: oss: Use kvzalloc() for local buffer allocations

2018-12-01T08:42:49+00:00

commit 65766ee0bf7fe8b3be80e2e1c3ef54ad59b29476 upstream.

PCM OSS layer may allocate a few temporary buffers, one for the core
read/write and another for the conversions via plugins.  Currently
both are allocated via vmalloc().  But as the allocation size is
equivalent with the PCM period size, the required size might be quite
small, depending on the application.

This patch replaces these vmalloc() calls with kvzalloc() for covering
small period sizes better.  Also, we use "z"-alloc variant here for
addressing the possible uninitialized access reported by syzkaller.

Reported-by: syzbot+1cb36954e127c98dd037@syzkaller.appspotmail.com
Cc: 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

ALSA: pcm: Fix endless loop for XRUN recovery in OSS emulation

2018-04-24T07:36:35+00:00

commit e15dc99dbb9cf99f6432e8e3c0b3a8f7a3403a86 upstream.

The commit 02a5d6925cd3 ("ALSA: pcm: Avoid potential races between OSS
ioctls and read/write") split the PCM preparation code to a locked
version, and it added a sanity check of runtime->oss.prepare flag
along with the change.  This leaded to an endless loop when the stream
gets XRUN: namely, snd_pcm_oss_write3() and co call
snd_pcm_oss_prepare() without setting runtime->oss.prepare flag and
the loop continues until the PCM state reaches to another one.

As the function is supposed to execute the preparation
unconditionally, drop the invalid state check there.

The bug was triggered by syzkaller.

Fixes: 02a5d6925cd3 ("ALSA: pcm: Avoid potential races between OSS ioctls and read/write")
Reported-by: syzbot+150189c103427d31a053@syzkaller.appspotmail.com
Reported-by: syzbot+7e3f31a52646f939c052@syzkaller.appspotmail.com
Reported-by: syzbot+4f2016cf5185da7759dc@syzkaller.appspotmail.com
Cc: 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman