commit c0bcdbdff3ff73a54161fca3cb8b6cdbd0bb8762 upstream.

When a TLV ioctl with numid zero is handled, the driver may spew a
kernel warning with a stack trace at each call.  The check was
intended obviously only for a kernel driver, but not for a user
interaction.  Let's fix it.

This was spotted by syzkaller fuzzer.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

An element instance can have several elements with the same feature.
Some userspace applications can add such an element instance by add
operation with the number of elements. Then, the element instance
gets a memory object to keep states of these elements.

But the element instance has just one memory object for the elements.
This causes the same result to each read/write operations to the
different elements.

This commit fixes this bug by allocating enough memory objects to the
element instance for each of elements.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

The commit [39d118677baa: ALSA: ctl: evaluate macro instead of
numerical value] replaced the numbers with constants, but one place
was replaced wrongly with a different type.  Fixed now.

Fixes: 39d118677baa ('ALSA: ctl: evaluate macro instead of numerical value')
Signed-off-by: Takashi Iwai <tiwai@suse.de>

currently some members related identical information are not fiiled
in returned parameter of SNDRV_CTL_IOCTL_ELEM_ADD. This is not better
for userspace application.

This commit copies information to returned value. When failing to copy
into userspace, the added elements are going to be removed. Then, no
applications can lock these elements between adding and removing because
these are already locked.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

In operations of SNDRV_CTL_IOCTL_ELEM_INFO, identical information in
returned value is cleared. This is not better to userspace application.

This commit confirms to return full identical information to the
operations.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

When event originator doesn't set numerical ID in identical information,
the event data includes no numerical ID, thus userspace applications
cannot identify the control just by unique ID in event data.

This commit fix this bug so as the event data includes all of identical
information.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

SNDRV_CTL_TLV_OP_XXX is defined but not used in core code. Instead,
raw numerical value is evaluated.

This commit replaces these values to these macros for better looking.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

In the commit [2225e79b9b03: 'ALSA: core: reduce stack usage related
to snd_ctl_new()'], the id field of the newly added kctl is untouched,
thus all attribute like name string remain empty.  The fix is just to
add the forgotten memcpy of the id field.

Fixes: 2225e79b9b03 ('ALSA: core: reduce stack usage related to snd_ctl_new()')
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

There was no check about the id string of user control elements, so we
accepted even a control element with an empty string, which is
obviously bogus.  This patch adds more sanity checks of id strings.

Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>