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2018-12-05ALSA: control: Fix race between adding and removing a user elementTakashi Iwai
commit e1a7bfe3807974e66f971f2589d4e0197ec0fced upstream. The procedure for adding a user control element has some window opened for race against the concurrent removal of a user element. This was caught by syzkaller, hitting a KASAN use-after-free error. This patch addresses the bug by wrapping the whole procedure to add a user control element with the card->controls_rwsem, instead of only around the increment of card->user_ctl_count. This required a slight code refactoring, too. The function snd_ctl_add() is split to two parts: a core function to add the control element and a part calling it. The former is called from the function for adding a user control element inside the controls_rwsem. One change to be noted is that snd_ctl_notify() for adding a control element gets called inside the controls_rwsem as well while it was called outside the rwsem. But this should be OK, as snd_ctl_notify() takes another (finer) rwlock instead of rwsem, and the call of snd_ctl_notify() inside rwsem is already done in another code path. Reported-by: syzbot+dc09047bce3820621ba2@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-30ALSA: core: Fix unexpected error at replacing user TLVTakashi Iwai
commit 88c54cdf61f508ebcf8da2d819f5dfc03e954d1d upstream. When user tries to replace the user-defined control TLV, the kernel checks the change of its content via memcmp(). The problem is that the kernel passes the return value from memcmp() as is. memcmp() gives a non-zero negative value depending on the comparison result, and this shall be recognized as an error code. The patch covers that corner-case, return 1 properly for the changed TLV. Fixes: 8aa9b586e420 ("[ALSA] Control API - more robust TLV implementation") Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-07-25Merge branch 'for-next' into for-linusTakashi Iwai
Merged 4.8 changes.
2016-07-08ALSA: ctl: Stop notification after disconnectionTakashi Iwai
snd_ctl_remove() has a notification for the removal event. It's superfluous when done during the device got disconnected. Although the notification itself is mostly harmless, it may potentially be harmful, and should be suppressed. Actually some components PCM may free ctl elements during the disconnect or free callbacks, thus it's no theoretical issue. This patch adds the check of card->shutdown flag for avoiding unnecessary notifications after (or during) the disconnect. Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-07-07ALSA: control: add dimension validator for userspace elementsTakashi Sakamoto
The 'dimen' field in struct snd_ctl_elem_info is used to compose all of members in the element as multi-dimensional matrix. The field has four members. Each member represents the width in each dimension level by element member unit. For example, if the members consist of typical two dimensional matrix, the dimen[0] represents the number of rows and dimen[1] represents the number of columns (or vise-versa). The total members in the matrix should be exactly the same as the number of members in the element, while current implementation has no validator of this information. In a view of userspace applications, the information must be valid so that it cannot cause any bugs such as buffer-over-run. This commit adds a validator of dimension information for userspace applications which add new element sets. When they add the element sets with wrong dimension information, they receive -EINVAL. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-01-18ALSA: control: Avoid kernel warnings from tlv ioctl with numid 0Takashi Iwai
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> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-04-13ALSA: ctl: fix to handle several elements added by one operation for ↵Takashi Sakamoto
userspace element 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>
2015-04-12ALSA: control: Fix a typo of SNDRV_CTL_ELEM_ACCESS_TLV_* with SNDRV_CTL_TLV_OP_*Takashi Iwai
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>
2015-04-11ALSA: ctl: fill identical information to return value when adding userspace ↵Takashi Sakamoto
elements 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>
2015-04-11ALSA: ctl: fix a bug to return no identical information in info operation ↵Takashi Sakamoto
for userspace controls 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>
2015-04-11ALSA: ctl: confirm to return all identical information in 'activate' eventTakashi Sakamoto
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>
2015-04-10ALSA: ctl: evaluate macro instead of numerical valueTakashi Sakamoto
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>
2015-03-13ALSA: control: Fix breakage of user ctl element additionTakashi Iwai
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>
2015-03-12Merge branch 'for-linus' into for-nextTakashi Iwai
2015-03-12ALSA: control: Add sanity checks for user ctl id name stringTakashi Iwai
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>
2015-03-10ALSA: core: Drop superfluous error/debug messages after malloc failuresTakashi Iwai
The kernel memory allocators already report the errors when the requested allocation fails, thus we don't need to warn it again in each caller side. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-03-10ALSA: core: reduce stack usage related to snd_ctl_new()Takashi Sakamoto
The callers of snd_ctl_new() need to have 'struct snd_kcontrol' data, and pass the data as template. Then, the function allocates the structure data again and copy from the template. This is a waste of resources. Especially, the callers use large stack for the template. This commit removes a need of template for the function, thus, changes the prototype of snd_ctl_new(). Furthermore, this commit changes the code of callers, snd_ctl_new1() and snd_ctl_elem_add() for better shape. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-03-10ALSA: core: use precomputed table to check userspace control paramsTakashi Sakamoto
The parameters can be decided in compile time. This commit adds precomputed table to reduce calculating time. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-02-09ALSA: control: fix failure to return new numerical ID in 'replace' event dataTakashi Sakamoto
In 'replace' event data, numerical ID of control is always invalid. This commit fix this bug so as the event data has renewed numerical ID for control. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-02-08ALSA: control: fix failure to return numerical ID in 'add' eventTakashi Sakamoto
Currently when adding a new control, the assigned numerical ID is not set for event data, thus userspace applications cannot realize it just by event data. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-02-02ALSA: Simplify snd_device_register() variantsTakashi Iwai
Now that all callers have been replaced with snd_device_register_for_dev(), let's drop the obsolete device registration code and concentrate only on the code handling struct device directly. That said, - remove the old snd_device_register(), - rename snd_device_register_for_dev() with snd_device_register(), - drop superfluous arguments from snd_device_register(), - change snd_unregister_device() to pass the device pointer directly Reviewed-by: Jaroslav Kysela <perex@perex.cz> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-02-02ALSA: control: Embed struct deviceTakashi Iwai
This patch embeds a struct device for the control device into the card object and avoid the device creation at registration time. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-02-02ALSA: control: Provide a helper to look for the preferred subdeviceTakashi Iwai
Instead of open-coding the search over the control file loop, provide a helper function for the preferred subdevice assigned to the current process. Reviewed-by: Jaroslav Kysela <perex@perex.cz> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-11-07ALSA: snd_ctl_activate_id(): Fix index look-upLars-Peter Clausen
We want to know the offset for the id that was passed to the function, not the offset of the first id of the control (which is always 0). Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-10-30ALSA: control: Add missing kerneldoc comments to exported functionsTakashi Iwai
A few functions have no proper documentation yet, so let's add them. Along with it, remove superfluous blank line between the closing brace and EXPORT_SYMBOL() line. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-10-20ALSA: control: Allow to pass items zero to snd_ctl_enum_info()Takashi Iwai
Although this is weird, some drivers want to allow empty control elements intentionally, e.g. the number of items may change depending on the firmware status. Let the function simply returning in such a case. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-10-20ALSA: control: Warn if too long string is passed to snd_ctl_enum_info()Takashi Iwai
This allows us to catch the bugs in drivers easily. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-07-15ALSA: control: Define SNDRV_CTL_TLV_OP_* constantsTakashi Iwai
Instead of hard-coded magic numbers, define constants for op_flag to tlv callbacks. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-06-18ALSA: control: Make sure that id->index does not overflowLars-Peter Clausen
The ALSA control code expects that the range of assigned indices to a control is continuous and does not overflow. Currently there are no checks to enforce this. If a control with a overflowing index range is created that control becomes effectively inaccessible and unremovable since snd_ctl_find_id() will not be able to find it. This patch adds a check that makes sure that controls with a overflowing index range can not be created. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Jaroslav Kysela <perex@perex.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-06-18ALSA: control: Handle numid overflowLars-Peter Clausen
Each control gets automatically assigned its numids when the control is created. The allocation is done by incrementing the numid by the amount of allocated numids per allocation. This means that excessive creation and destruction of controls (e.g. via SNDRV_CTL_IOCTL_ELEM_ADD/REMOVE) can cause the id to eventually overflow. Currently when this happens for the control that caused the overflow kctl->id.numid + kctl->count will also over flow causing it to be smaller than kctl->id.numid. Most of the code assumes that this is something that can not happen, so we need to make sure that it won't happen Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Jaroslav Kysela <perex@perex.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-06-18ALSA: control: Don't access controls outside of protected regionsLars-Peter Clausen
A control that is visible on the card->controls list can be freed at any time. This means we must not access any of its memory while not holding the controls_rw_lock. Otherwise we risk a use after free access. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Jaroslav Kysela <perex@perex.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-06-18ALSA: control: Fix replacing user controlsLars-Peter Clausen
There are two issues with the current implementation for replacing user controls. The first is that the code does not check if the control is actually a user control and neither does it check if the control is owned by the process that tries to remove it. That allows userspace applications to remove arbitrary controls, which can cause a user after free if a for example a driver does not expect a control to be removed from under its feed. The second issue is that on one hand when a control is replaced the user_ctl_count limit is not checked and on the other hand the user_ctl_count is increased (even though the number of user controls does not change). This allows userspace, once the user_ctl_count limit as been reached, to repeatedly replace a control until user_ctl_count overflows. Once that happens new controls can be added effectively bypassing the user_ctl_count limit. Both issues can be fixed by instead of open-coding the removal of the control that is to be replaced to use snd_ctl_remove_user_ctl(). This function does proper permission checks as well as decrements user_ctl_count after the control has been removed. Note that by using snd_ctl_remove_user_ctl() the check which returns -EBUSY at beginning of the function if the control already exists is removed. This is not a problem though since the check is quite useless, because the lock that is protecting the control list is released between the check and before adding the new control to the list, which means that it is possible that a different control with the same settings is added to the list after the check. Luckily there is another check that is done while holding the lock in snd_ctl_add(), so we'll rely on that to make sure that the same control is not added twice. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Jaroslav Kysela <perex@perex.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-06-18ALSA: control: Protect user controls against concurrent accessLars-Peter Clausen
The user-control put and get handlers as well as the tlv do not protect against concurrent access from multiple threads. Since the state of the control is not updated atomically it is possible that either two write operations or a write and a read operation race against each other. Both can lead to arbitrary memory disclosure. This patch introduces a new lock that protects user-controls from concurrent access. Since applications typically access controls sequentially than in parallel a single lock per card should be fine. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Jaroslav Kysela <perex@perex.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-02-14ALSA: control: Use standard printk helpersTakashi Iwai
Use dev_err() & co as much as possible. If not available (no device assigned at the calling point), use pr_xxx() helpers instead. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2014-02-10ALSA: Replace with IS_ENABLED()Takashi Iwai
Replace the lengthy #if defined(XXX) || defined(XXX_MODULE) with the new IS_ENABLED() macro. The patch still doesn't cover all ifdefs. For example, the dependency on CONFIG_GAMEPORT is still open-coded because this also has an extra dependency on MODULE. Similarly, an open-coded ifdef in pcm_oss.c and some sequencer-related stuff are left untouched. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2013-03-12ALSA: add/change some comments describing function return valuesYacine Belkadi
script/kernel-doc reports the following type of warnings (when run in verbose mode): Warning(sound/core/init.c:152): No description found for return value of 'snd_card_create' To fix that: - add missing descriptions of function return values - use "Return:" sections to describe those return values Along the way: - complete some descriptions - fix some typos Signed-off-by: Yacine Belkadi <yacine.belkadi.1@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2012-10-30ALSA: Avoid endless sleep after disconnectTakashi Iwai
When disconnect callback is called, each component should wake up sleepers and check card->shutdown flag for avoiding the endless sleep blocking the proper resource release. Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2012-10-30ALSA: Add a reference counter to card instanceTakashi Iwai
For more strict protection for wild disconnections, a refcount is introduced to the card instance, and let it up/down when an object is referred via snd_lookup_*() in the open ops. The free-after-last-close check is also changed to check this refcount instead of the empty list, too. Reported-by: Matthieu CASTET <matthieu.castet@parrot.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2012-09-06ALSA: control: Fix missing VOLATILE flag at creating controlsTakashi Iwai
The SNDRV_CTL_ELEM_ACCESS_VOLATILE bit flag wasn't properly inherited at creating control elements via snd_ctl_new1(). Signed-off-by: Takashi Iwai <tiwai@suse.de>
2012-03-13ALSA: control - Fixe a trailing white space errorJeffrin Jose
Fixed a trailing white space error detected in sound/core/control.c by checkpatch.pl script. Signed-off-by: Jeffrin Jose <ahiliation@yahoo.co.in> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-11-06Merge branch 'modsplit-Oct31_2011' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux * 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits) Revert "tracing: Include module.h in define_trace.h" irq: don't put module.h into irq.h for tracking irqgen modules. bluetooth: macroize two small inlines to avoid module.h ip_vs.h: fix implicit use of module_get/module_put from module.h nf_conntrack.h: fix up fallout from implicit moduleparam.h presence include: replace linux/module.h with "struct module" wherever possible include: convert various register fcns to macros to avoid include chaining crypto.h: remove unused crypto_tfm_alg_modname() inline uwb.h: fix implicit use of asm/page.h for PAGE_SIZE pm_runtime.h: explicitly requires notifier.h linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h miscdevice.h: fix up implicit use of lists and types stop_machine.h: fix implicit use of smp.h for smp_processor_id of: fix implicit use of errno.h in include/linux/of.h of_platform.h: delete needless include <linux/module.h> acpi: remove module.h include from platform/aclinux.h miscdevice.h: delete unnecessary inclusion of module.h device_cgroup.h: delete needless include <linux/module.h> net: sch_generic remove redundant use of <linux/module.h> net: inet_timewait_sock doesnt need <linux/module.h> ... Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in - drivers/media/dvb/frontends/dibx000_common.c - drivers/media/video/{mt9m111.c,ov6650.c} - drivers/mfd/ab3550-core.c - include/linux/dmaengine.h
2011-11-06ALSA: control: remove compilation warning on 32-bitOlof Johansson
This was introduced by 'ALSA: control: add support for ENUMERATED user space controls' which adds a u64 variable that gets cast to a pointer: sound/core/control.c: In function 'snd_ctl_elem_init_enum_names': sound/core/control.c:1089: warning: cast to pointer from integer of different size Cast to uintptr_t before casting to pointer to avoid the warning. Signed-off-by: Olof Johansson <olof@lixom.net> [cl: replace long with uintptr_t] Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-10-31sound: Add module.h to the previously silent sound usersPaul Gortmaker
Lots of sound drivers were getting module.h via the implicit presence of it in <linux/device.h> but we are going to clean that up. So fix up those users now. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-09ALSA: control: add support for ENUMERATED user space controlsClemens Ladisch
Handling of user control elements was implemented for all types except ENUMERATED. This type will be needed for the device-specific mixers of upcoming FireWire drivers. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-08-24ALSA: core: release the constraint check for replace opsLu Guanqun
Suppose the ALSA card already has a number of MAX_USER_CONTROLS controls, and the user wants to replace one, it should not fail at this condition check. Signed-off-by: Lu Guanqun <guanqun.lu@intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-08-24ALSA: core: trivial code style fixLu Guanqun
remove trailing tab on the line. Signed-off-by: Lu Guanqun <guanqun.lu@intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-05-26ALSA: core: remove unused variables.Luca Tettamanti
Drop a few variables that are never read. Signed-off-by: Luca Tettamanti <kronos.it@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-03-22ALSA: Add snd_ctl_replace() to dynamically replace a controlDimitris Papastamos
Add a function to dynamically replace a given control. If the control does not already exist, a third parameter is used to determine whether to actually add that control. This is useful in cases where downloadable firmware at runtime can add or replace existing controls. A separate patch needs to be made to allow ALSA Mixer to render the replaced controls on the fly. Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-03-18Merge branch 'topic/misc' into for-linusTakashi Iwai
2011-03-11ALSA: Add snd_ctl_activate_id()Takashi Iwai
Added a new API function snd_ctl_activate_id() for activate / inactivate the control element dynamically. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>