[ Upstream commit 1a462be52f4505a2719631fb5aa7bfdbd37bfd8d ]
In the commit 8e85def5723e ("ALSA: hda: enable regmap internal
locking"), we re-enabled the regmap lock due to the reported
regression that showed the possible concurrent accesses. It was a
temporary workaround, and there are still a few opened races even
after the revert. In this patch, we cover those still opened windows
with a proper mutex lock and disable the regmap internal lock again.
First off, the patch introduces a new snd_hdac_device.regmap_lock
mutex that is applied for each snd_hdac_regmap_*() call, including
read, write and update helpers. The mutex is applied carefully so
that it won't block the self-power-up procedure in the helper
function. Also, this assures the protection for the accesses without
regmap, too.
The snd_hdac_regmap_update_raw() is refactored to use the standard
regmap_update_bits_check() function instead of the open-code. The
non-regmap case is still open-coded but it's an easy part. The all
read and write operations are in the single mutex protection, so it's
now race-free.
In addition, a couple of new helper functions are added:
snd_hdac_regmap_update_raw_once() and snd_hdac_regmap_sync(). Both
are called from HD-audio legacy driver. The former is to initialize
the given verb bits but only once when it's not initialized yet. Due
to this condition, the function invokes regcache_cache_only(), and
it's now performed inside the regmap_lock (formerly it was racy) too.
The latter function is for simply invoking regcache_sync() inside the
regmap_lock, which is called from the codec resume call path.
Along with that, the HD-audio codec driver code is slightly modified /
simplified to adapt those new functions.
And finally, snd_hdac_regmap_read_raw(), *_write_raw(), etc are
rewritten with the helper macro. It's just for simplification because
the code logic is identical among all those functions.
Tested-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20200109090104.26073-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit c1f6e3c818dd734c30f6a7eeebf232ba2cf3181d upstream.
The rawmidi core allows user to resize the runtime buffer via ioctl,
and this may lead to UAF when performed during concurrent reads or
writes: the read/write functions unlock the runtime lock temporarily
during copying form/to user-space, and that's the race window.
This patch fixes the hole by introducing a reference counter for the
runtime buffer read/write access and returns -EBUSY error when the
resize is performed concurrently against read/write.
Note that the ref count field is a simple integer instead of
refcount_t here, since the all contexts accessing the buffer is
basically protected with a spinlock, hence we need no expensive atomic
ops. Also, note that this busy check is needed only against read /
write functions, and not in receive/transmit callbacks; the race can
happen only at the spinlock hole mentioned in the above, while the
whole function is protected for receive / transmit callbacks.
Reported-by: butt3rflyh4ck <butterflyhuangxx@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/CAFcO6XMWpUVK_yzzCpp8_XP7+=oUpQvuBeCbMffEDkpe8jWrfg@mail.gmail.com
Link: https://lore.kernel.org/r/s5heerw3r5z.wl-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a22ae72b86a4f754e8d25fbf9ea5a8f77365e531 upstream.
v5.4 changes in soc-core tightened the checks on soc_dapm_add_routes,
which results in the ASoC card probe failing.
Introduce a flag to be set in machine drivers to prevent the probe
from stopping in case of incomplete topologies or missing routes. This
flag is for backwards compatibility only and shall not be used for
newer machine drivers.
Example with an HDaudio card with a bad topology:
[ 236.177898] skl_hda_dsp_generic skl_hda_dsp_generic: ASoC: Failed to
add route iDisp1_out -> direct -> iDisp1 Tx
[ 236.177902] skl_hda_dsp_generic skl_hda_dsp_generic:
snd_soc_bind_card: snd_soc_dapm_add_routes failed: -19
with the disable_route_checks set:
[ 64.031657] skl_hda_dsp_generic skl_hda_dsp_generic: ASoC: Failed to
add route iDisp1_out -> direct -> iDisp1 Tx
[ 64.031661] skl_hda_dsp_generic skl_hda_dsp_generic:
snd_soc_bind_card: disable_route_checks set, ignoring errors on
add_routes
Fixes: daa480bde6b3a9 ("ASoC: soc-core: tidyup for snd_soc_dapm_add_routes()")
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/20200309192744.18380-2-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Takashi Iwai