snd_ctl_elem_init_enum_names() advances pointer p through the names
buffer while decrementing buf_len. If buf_len reaches zero but items
remain, the next iteration calls strnlen(p, 0).
While strnlen(p, 0) returns 0 and would hit the existing name_len == 0
error path, CONFIG_FORTIFY_SOURCE's fortified strnlen() first checks
maxlen against __builtin_dynamic_object_size(). When Clang loses track
of p's object size inside the loop, this triggers a BRK exception panic
before the return value is examined.
Add a buf_len == 0 guard at the loop entry to prevent calling fortified
strnlen() on an exhausted buffer.
Found by kernel fuzz testing through Xiaomi Smartphone.
Fixes: 8d448162bd ("ALSA: control: add support for ENUMERATED user space controls")
Cc: stable@vger.kernel.org
Signed-off-by: Ziqing Chen <chenziqing@xiaomi.com>
Link: https://patch.msgid.link/20260414132437.261304-1-chenziqing@xiaomi.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The put() operation is expected to return:
1) 0 on success if no changes were made
2) 1 on success if changes were made
3) error code otherwise
Currently 2) is usually ignored when writing control-operations. While
forcing compliance is not an option right now, make it easier for
developers to adhere to the expectations and notice problems by logging
them when CONFIG_SND_CTL_DEBUG is enabled.
Due to large size of struct snd_ctl_elem_value, 'value_buf' is provided
as a reusable buffer for kctl->put() verification. This prevents
exhausting the stack when verifying the operation.
>From user perspective, patch introduces a new trace/events category
'snd_ctl' containing a single 'snd_ctl_put' event type. Log sample:
amixer-1086 [003] ..... 8.035939: snd_ctl_put: success: expected=0, actual=0 for ctl numid=1, iface=MIXER, name='Master Playback Volume', index=0, device=0, subdevice=0, card=0
amixer-1087 [003] ..... 8.938721: snd_ctl_put: success: expected=1, actual=1 for ctl numid=1, iface=MIXER, name='Master Playback Volume', index=0, device=0, subdevice=0, card=0
amixer-1088 [003] ..... 9.631470: snd_ctl_put: success: expected=1, actual=1 for ctl numid=1, iface=MIXER, name='Master Playback Volume', index=0, device=0, subdevice=0, card=0
amixer-1089 [000] ..... 9.636786: snd_ctl_put: fail: expected=1, actual=0 for ctl numid=5, iface=MIXER, name='Loopback Mute', index=0, device=0, subdevice=0, card=0
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260224205619.584795-1-cezary.rojewski@intel.com
This is the exact same thing as the 'alloc_obj()' version, only much
smaller because there are a lot fewer users of the *alloc_flex()
interface.
As with alloc_obj() version, this was done entirely with mindless brute
force, using the same script, except using 'flex' in the pattern rather
than 'objs*'.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
We used to have a variable declaration with __free() initialized with
NULL. This was to keep the old coding style rule, but recently it's
relaxed and rather recommends to follow the new rule to declare in
place of use for __free() -- which avoids potential deadlocks or UAFs
with nested cleanups.
Although the current code has no bug, per se, let's follow the new
standard and move the declaration to the place of assignment (or
directly assign the allocated result) instead of NULL initializations.
Fixes: 7dba48a474 ("ALSA: control_led: Use guard() for locking")
Fixes: 1052d98822 ("ALSA: control: Use automatic cleanup of kfree()")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20251216140634.171890-3-tiwai@suse.de
ASoC: Fixes for v6.12
A bunch of fixes here that came in during the merge window and the first
week of release, plus some new quirks and device IDs. There's nothing
major here, it's a bit bigger than it might've been due to there being
no fixes sent during the merge window due to your vacation.
This patch doesn't change runtime at all, it's just for kernel hardening.
The "count" here comes from the user and on 32bit systems, it leads to
integer wrapping when we pass it to compute_user_elem_size():
alloc_size = compute_user_elem_size(private_size, count);
However, the integer over is harmless because later "count" is checked
when we pass it to snd_ctl_new():
err = snd_ctl_new(&kctl, count, access, file);
These days as part of kernel hardening we're trying to avoid integer
overflows when they affect size_t type. So to avoid the integer overflow
copy the check from snd_ctl_new() and do it at the start of the
snd_ctl_elem_add() function as well.
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://patch.msgid.link/5457e8c1-01ff-4dd9-b49c-15b817f65ee7@stanley.mountain
Signed-off-by: Takashi Iwai <tiwai@suse.de>
no_llseek had been defined to NULL two years ago, in commit 868941b144
("fs: remove no_llseek")
To quote that commit,
At -rc1 we'll need do a mechanical removal of no_llseek -
git grep -l -w no_llseek | grep -v porting.rst | while read i; do
sed -i '/\<no_llseek\>/d' $i
done
would do it.
Unfortunately, that hadn't been done. Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
.llseek = no_llseek,
so it's obviously safe.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We used to wrap with no_free_ptr() for the return value from
memdup_user() with errors where the auto cleanup is applied. This was
a workaround because the initial implementation of kfree auto-cleanup
checked only NULL pointers.
Since recently, though, the kfree auto-cleanup checks with
IS_ERR_OR_NULL() (by the commit cd7eb8f83f ("mm/slab: make
__free(kfree) accept error pointers")), hence those workarounds became
superfluous. Let's drop them now.
Link: https://patch.msgid.link/20240902075246.3743-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
For a fast look-up of a control element via either numid or name
matching (enabled via CONFIG_SND_CTL_FAST_LOOKUP), a locking isn't
needed at all thanks to Xarray. OTOH, the locking is still needed for
a slow linked-list traversal, and that's rather a rare case.
In this patch, we reduce the use of locking at snd_ctl_find_*() API
functions, and switch from controls_rwsem to controls_rwlock for
avoiding unnecessary lock inversions. This also resulted in a nice
cleanup, as *_unlocked() version of snd_ctl_find_*() APIs can be
dropped.
snd_ctl_find_id_mixer_unlocked() is still left just as an alias of
snd_ctl_find_id_mixer(), since soc-card.c has a wrapper and there are
several users. Once after converting there, we can remove it later.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20240809104234.8488-3-tiwai@suse.de
We'll re-use the existing rwlock for the protection of control list
lookup, too, and now rename it to a more generic name.
This is a preliminary change, only the rename of the struct field
here, no functional changes.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20240809104234.8488-2-tiwai@suse.de
The code path for kcontrol accesses have often nested locks of both
card's controls_rwsem and power_ref, and applies in that order.
However, what could take much longer is the latter, power_ref; it
waits for the power state of the device, and it pretty much depends on
the user's action.
This patch swaps the locking order of those locks to a more natural
way, namely, power_ref -> controls_rwsem, in order to shorten the time
of possible nested locks. For consistency, power_ref is taken always
in the top-level caller side (that is, *_user() functions and the
ioctl handler itself).
Link: https://patch.msgid.link/20240729160659.4516-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
struct snd_kcontrol contains a flex array of snd_kcontrol_volatile
objects at its end, and the array size is stored in count field.
This can be annotated gracefully with __counted_by() for catching
possible array overflows.
One additional change is the order of the count field initialization;
The assignment of the count field is moved before assignment of vd[]
elements for avoiding false-positive warnings from compilers.
Link: https://patch.msgid.link/20240726152840.8629-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
There are lots of code checking NULL for kcontrol passed to
snd_ctl_remove() in the caller side. Let's make snd_ctl_remove()
accepting the NULL kcontrol instead a la free(), so that we can clean
up the caller side.
Link: https://lore.kernel.org/20240617100529.6667-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Although we have already a mechanism for sanity checks of input values
for control writes, it's not applied unless the kconfig
CONFIG_SND_CTL_INPUT_VALIDATION is set due to the performance reason.
Nevertheless, it still makes sense to apply the same check for user
elements despite of its cost, as that's the only way to filter out the
invalid values; the user controls are handled solely in ALSA core
code, and there is no corresponding driver, after all.
This patch adds the same input value validation for user control
elements at its put callback. The kselftest will be happier with this
change, as the incorrect values will be bailed out now with errors.
For other normal controls, the check is applied still only when
CONFIG_SND_CTL_INPUT_VALIDATION is set.
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Closes: https://lore.kernel.org/r/1d44be36-9bb9-4d82-8953-5ae2a4f09405@molgen.mpg.de
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/20240616073454.16512-4-tiwai@suse.de
We can simplify the code gracefully with new guard() macro and co for
automatic cleanup of locks.
The lops calls under multiple rwsems are factored out as a simple
macro, so that it can be called easily from snd_ctl_dev_register()
and snd_ctl_dev_disconnect().
There are a few remaining explicit rwsem and spinlock calls, and those
are the places where the lock downgrade happens or where the temporary
unlock/relocking happens -- which guard() doens't cover well yet.
Only the code refactoring, and no functional changes.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20240227085306.9764-9-tiwai@suse.de
There are common patterns where a temporary buffer is allocated and
freed at the exit, and those can be simplified with the recent cleanup
mechanism via __free(kfree).
A caveat is that some allocations are memdup_user() and they return an
error pointer instead of NULL. Those need special cares and the value
has to be cleared with no_free_ptr() at the allocation error path.
Other than that, the conversions are straightforward.
No functional changes, only code refactoring.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20240222111509.28390-3-tiwai@suse.de
Embedding the ctl_dev in the snd_card object may result in UAF when
the delayed kobj release is used; at the delayed kobj release, it
still accesses the struct device itself while the card memory (that
embeds the struct device) may be already gone.
As a workaround, detach the struct device from the card object by
allocating via the new snd_device_alloc() helper. The rest are just
replacing ctl_dev access to the pointer.
This is based on the fix Curtis posted initially. In this patch, the
changes are split and use the new helper function instead.
Link: https://lore.kernel.org/r/20230801171928.1460120-1-cujomalainey@chromium.org
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Curtis Malainey <cujomalainey@chromium.org>
Tested-by: Curtis Malainey <cujomalainey@chromium.org>
Link: https://lore.kernel.org/r/20230816160252.23396-3-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Now all needed callers have been replaced with *_locked() versions,
let's turn on the locking in snd_ctl_find_id() and
snd_ctl_find_numid().
This patch also adds the lockdep assertions for debugging, too.
Link: https://lore.kernel.org/r/20230718141304.1032-11-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Ziqing ChenandTakashi Iwai
Cezary RojewskiandTakashi Iwai
Linus Torvalds
Kees Cook
Kuninori MorimotoandTakashi Iwai
Dan CarpenterandTakashi Iwai
Al ViroandLinus Torvalds