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2017-08-15ALSA: seq: 2nd attempt at fixing race creating a queueDaniel Mentz
commit 4842e98f26dd80be3623c4714a244ba52ea096a8 ("ALSA: seq: Fix race at creating a queue") attempted to fix a race reported by syzkaller. That fix has been described as follows: " When a sequencer queue is created in snd_seq_queue_alloc(),it adds the new queue element to the public list before referencing it. Thus the queue might be deleted before the call of snd_seq_queue_use(), and it results in the use-after-free error, as spotted by syzkaller. The fix is to reference the queue object at the right time. " Even with that fix in place, syzkaller reported a use-after-free error. It specifically pointed to the last instruction "return q->queue" in snd_seq_queue_alloc(). The pointer q is being used after kfree() has been called on it. It turned out that there is still a small window where a race can happen. The window opens at snd_seq_ioctl_create_queue()->snd_seq_queue_alloc()->queue_list_add() and closes at snd_seq_ioctl_create_queue()->queueptr()->snd_use_lock_use(). Between these two calls, a different thread could delete the queue and possibly re-create a different queue in the same location in queue_list. This change prevents this situation by calling snd_use_lock_use() from snd_seq_queue_alloc() prior to calling queue_list_add(). It is then the caller's responsibility to call snd_use_lock_free(&q->use_lock). Fixes: 4842e98f26dd ("ALSA: seq: Fix race at creating a queue") Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Daniel Mentz <danielmentz@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-08-11ALSA: seq: Fix CONFIG_SND_SEQ_MIDI dependencyTakashi Iwai
The commit 0181307abc1d ("ALSA: seq: Reorganize kconfig and build") rewrote the dependency of each sequencer module in a standard way, but there was one change applied mistakenly: CONFIG_SND_SEQ_MIDI isn't enabled properly by CONFIG_SND_RAWMIDI. I seem to have changed the wrong one instead, CONFIG_SND_SEQ_MIDI_EMUL, which is eventually reverse-selected by CONFIG_SND_SEQ_MIDI itself. This ended up the lack of snd-seq-midi module as reported below. The fix is to put def_tristate properly to CONFIG_SND_SEQ_MIDI instead of *_MIDI_EMUL entry. Fixes: 0181307abc1d ("ALSA: seq: Reorganize kconfig and build") Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=196633 Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-07-06Merge tag 'sound-4.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound Pull sound updates from Takashi Iwai: "This development cycle resulted in a fair amount of changes in both core and driver sides. The most significant change in ALSA core is about PCM. Also the support of of-graph card and the new DAPM widget for DSP are noteworthy changes in ASoC core. And there're lots of small changes splat over the tree, as you can see in diffstat. Below are a few highlights: ALSA core: - Removal of set_fs() hackery from PCM core stuff, and the code reorganization / optimization thereafter - Improved support of PCM ack ops, and a new ABI for improved control/status mmap handling - Lots of constifications in various codes ASoC core: - The support of of-graph card, which may work as a better generic device for a replacement of simple-card - New widget types intended mainly for use with DSPs ASoC drivers: - New drivers for Allwinner V3s SoCs - Ensonic ES8316 codec support - More Intel SKL and KBL works - More device support for Intel SST Atom (mostly for cheap tablets and 2-in-1 devices) - Support for Rockchip PDM controllers - Support for STM32 I2S and S/PDIF controllers - Support for ZTE AUD96P22 codecs HD-audio: - Support of new Realtek codecs (ALC215/ALC285/ALC289), more quirks for HP and Dell machines - A few more fixes for i915 component binding" * tag 'sound-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (418 commits) ALSA: hda - Fix unbalance of i915 module refcount ASoC: Intel: Skylake: Remove driver debugfs exit ASoC: Intel: Skylake: explicitly add the headers sst-dsp.h ALSA: hda/realtek - Remove GPIO_MASK ALSA: hda/realtek - Fix typo of pincfg for Dell quirk ALSA: pcm: add a documentation for tracepoints ALSA: atmel: ac97c: fix error return code in atmel_ac97c_probe() ALSA: x86: fix error return code in hdmi_lpe_audio_probe() ASoC: Intel: Skylake: Add support to read firmware registers ASoC: Intel: Skylake: Add sram address to sst_addr structure ASoC: Intel: Skylake: Debugfs facility to dump module config ASoC: Intel: Skylake: Add debugfs support ASoC: fix semicolon.cocci warnings ASoC: rt5645: Add quirk override by module option ASoC: rsnd: make arrays path and cmd_case static const ASoC: audio-graph-card: add widgets and routing for external amplifier support ASoC: audio-graph-card: update bindings for amplifier support ASoC: rt5665: calibration should be done before jack detection ASoC: rsnd: constify dev_pm_ops structures. ASoC: nau8825: change crosstalk-bypass property to bool type ...
2017-06-20sched/wait: Rename wait_queue_t => wait_queue_entry_tIngo Molnar
Rename: wait_queue_t => wait_queue_entry_t 'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue", but in reality it's a queue *entry*. The 'real' queue is the wait queue head, which had to carry the name. Start sorting this out by renaming it to 'wait_queue_entry_t'. This also allows the real structure name 'struct __wait_queue' to lose its double underscore and become 'struct wait_queue_entry', which is the more canonical nomenclature for such data types. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-16ALSA: seq: Follow standard EXPORT_SYMBOL() declarationsTakashi Iwai
Just a tidy up to follow the standard EXPORT_SYMBOL*() declarations in order to improve grep-ability. - Move EXPORT_SYMBOL*() to the position right after its definition - Remove superfluous blank line before EXPORT_SYMBOL*() lines Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-06-12ALSA: seq: Allow the modular sequencer registrationTakashi Iwai
Many drivers bind the sequencer stuff in off-load by another driver module, so that it's loaded only on demand. In the current code, this mechanism doesn't work when the driver is built-in while the sequencer is module. We check with IS_REACHABLE() and enable only when the sequencer is in the same level of build. However, this is basically a overshoot. The binder code (snd-seq-device) is an individual module from the sequencer core (snd-seq), and we just have to make the former a built-in while keeping the latter a module for allowing the scenario like the above. This patch achieves that by rewriting Kconfig slightly. Now, a driver that provides the manual sequencer device binding should select CONFIG_SND_SEQ_DEVICE in a way as select SND_SEQ_DEVICE if SND_SEQUENCER != n Note that the "!=n" is needed here to avoid the influence of the sequencer core is module while the driver is built-in. Also, since rawmidi.o may be linked with snd_seq_device.o when built-in, we have to shuffle the code to make the linker happy. (the kernel linker isn't smart enough yet to handle such a case.) That is, snd_seq_device.c is moved to sound/core from sound/core/seq, as well as Makefile. Last but not least, the patch replaces the code using IS_REACHABLE() with IS_ENABLED(), since now the condition meets always when enabled. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-06-09ALSA: seq: Reorganize kconfig and buildTakashi Iwai
This is a slightly intensive rewrite of Kconfig and Makefile about ALSA sequencer stuff. The first major change is that the kconfig items for the sequencer are moved to sound/core/seq/Kconfig. OK, that's easy. The substantial change is that, instead of hackish top-level module selection in Makefile, we define a Kconfig item for each sequencer module. The driver that requires such sequencer components select exclusively the kconfig items. This is more straightforward and standard way. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-06-09ALSA: seq: Allow the tristate build of OSS emulationTakashi Iwai
Currently OSS sequencer emulation is tied with ALSA sequencer core, both are built in the same level; i.e. when CONFIG_SND_SEQUENCER=y, the OSS sequencer emulation is also always built-in, even though the functionality can be built as an individual module. This patch changes the rule and allows users to build snd-seq-oss module while others are built-in. Essentially, it's just a few simple changes in Kconfig and Makefile. Some driver codes like opl3 need to convert from the simple ifdef to IS_ENABLED(). But that's all. You might wonder how about the dependency: right, it can be messy, but it still works. Since we rewrote the sequencer binding with the standard bus, the driver can be bound at any time on demand. So, the synthesizer driver module can be loaded individually from the OSS emulation core before/after it. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-04-13ALSA: seq: Don't break snd_use_lock_sync() loop by timeoutTakashi Iwai
The snd_use_lock_sync() (thus its implementation snd_use_lock_sync_helper()) has the 5 seconds timeout to break out of the sync loop. It was introduced from the beginning, just to be "safer", in terms of avoiding the stupid bugs. However, as Ben Hutchings suggested, this timeout rather introduces a potential leak or use-after-free that was apparently fixed by the commit 2d7d54002e39 ("ALSA: seq: Fix race during FIFO resize"): for example, snd_seq_fifo_event_in() -> snd_seq_event_dup() -> copy_from_user() could block for a long time, and snd_use_lock_sync() goes timeout and still leaves the cell at releasing the pool. For fixing such a problem, we remove the break by the timeout while still keeping the warning. Suggested-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-03-24ALSA: seq: Fix race during FIFO resizeTakashi Iwai
When a new event is queued while processing to resize the FIFO in snd_seq_fifo_clear(), it may lead to a use-after-free, as the old pool that is being queued gets removed. For avoiding this race, we need to close the pool to be deleted and sync its usage before actually deleting it. The issue was spotted by syzkaller. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-03-21ALSA: seq: Fix racy cell insertions during snd_seq_pool_done()Takashi Iwai
When snd_seq_pool_done() is called, it marks the closing flag to refuse the further cell insertions. But snd_seq_pool_done() itself doesn't clear the cells but just waits until all cells are cleared by the caller side. That is, it's racy, and this leads to the endless stall as syzkaller spotted. This patch addresses the racy by splitting the setup of pool->closing flag out of snd_seq_pool_done(), and calling it properly before snd_seq_pool_done(). BugLink: http://lkml.kernel.org/r/CACT4Y+aqqy8bZA1fFieifNxR2fAfFQQABcBHj801+u5ePV0URw@mail.gmail.com Reported-and-tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-03-02sched/headers: Prepare to move signal wakeup & sigpending methods from ↵Ingo Molnar
<linux/sched.h> into <linux/sched/signal.h> Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-28ALSA: seq: Fix link corruption by event error handlingTakashi Iwai
The sequencer FIFO management has a bug that may lead to a corruption (shortage) of the cell linked list. When a sequencer client faces an error at the event delivery, it tries to put back the dequeued cell. When the first queue was put back, this forgot the tail pointer tracking, and the link will be screwed up. Although there is no memory corruption, the sequencer client may stall forever at exit while flushing the pending FIFO cells in snd_seq_pool_done(), as spotted by syzkaller. This patch addresses the missing tail pointer tracking at snd_seq_fifo_cell_putback(). Also the patch makes sure to clear the cell->enxt pointer at snd_seq_fifo_event_in() for avoiding a similar mess-up of the FIFO linked list. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-02-20Merge branch 'for-next' into for-linusTakashi Iwai
2017-02-08ALSA: seq: Fix race at creating a queueTakashi Iwai
When a sequencer queue is created in snd_seq_queue_alloc(),it adds the new queue element to the public list before referencing it. Thus the queue might be deleted before the call of snd_seq_queue_use(), and it results in the use-after-free error, as spotted by syzkaller. The fix is to reference the queue object at the right time. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-02-07Merge branch 'for-linus' into for-nextTakashi Iwai
2017-02-06ALSA: seq: Don't handle loop timeout at snd_seq_pool_done()Takashi Iwai
snd_seq_pool_done() syncs with closing of all opened threads, but it aborts the wait loop with a timeout, and proceeds to the release resource even if not all threads have been closed. The timeout was 5 seconds, and if you run a crazy stuff, it can exceed easily, and may result in the access of the invalid memory address -- this is what syzkaller detected in a bug report. As a fix, let the code graduate from naiveness, simply remove the loop timeout. BugLink: http://lkml.kernel.org/r/CACT4Y+YdhDV2H5LLzDTJDVF-qiYHUHhtRaW4rbb4gUhTCQB81w@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2017-01-12ALSA: seq: Constify snd_rawmidi_opsTakashi Iwai
Now snd_rawmidi_ops is maintained as a const pointer in snd_rawmidi, we can constify the definitions. Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-10-25ALSA: seq: Fix time account regressionTakashi Iwai
The recent rewrite of the sequencer time accounting using timespec64 in the commit [3915bf294652: ALSA: seq_timer: use monotonic times internally] introduced a bad regression. Namely, the time reported back doesn't increase but goes back and forth. The culprit was obvious: the delta is stored to the result (cur_time = delta), instead of adding the delta (cur_time += delta)! Let's fix it. Fixes: 3915bf294652 ('ALSA: seq_timer: use monotonic times internally') Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=177571 Reported-by: Yves Guillemot <yc.guillemot@wanadoo.fr> Cc: <stable@vger.kernel.org> # v4.8+ Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-10-12ALSA: seq: fix passing wrong pointer in function call of compatibility layerTakashi Sakamoto
This commit is a fix for Linux 4.9-rc1. In former commit, a function call of compatibility layer for ALSA sequencer core was obsoleted by an alternative. Although, the alternative gets a pointer to kernel stack due to mis-programming. As a result, ALSA sequencer core unexpectedly refers over kernel stack. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: 8ce8eb601c71 ("ALSA: seq: add an alternative way to handle ioctl requests") Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-09-13ALSA: seq: fix to copy from/to user spaceTakashi Sakamoto
When checking value of request for copy operation, current implementation compares shifted value to macros, while these macros are already shifted. As a result, it never performs to copy from/to user space. This commit fixes the bug. Fixes: 8ce8eb601c71('ALSA: seq: add an alternative way to handle ioctl requests' Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-31ALSA: seq: initialize whole fields of automatic variable with union typeTakashi Sakamoto
Currently, automatic variable of 'union ioctl_arg' type is initialized by designated initialization. Although, the actual effect is interpretation of early element of int type and initialization of 'int pversion'. Therefore the first field corresponding to int type is initialized to zero. This is against my expectation to initialize whole fields. This commit uses memset() to initialize the variable, instead of designated initialization. Fixes: 04a56dd8ed0d ('ALSA: seq: change ioctl command operation to get data in kernel space') Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-22ALSA: seq: obsolete change of address limitTakashi Sakamoto
Former commits change existent functions so that they don't handle data in kernel space. Copying from/to userspace is done outside of the functions, thus no need to change address limit of running task. This commit obsoletes get_fs()/set_fs() and applies corresponding changes. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-22ALSA: seq: change ioctl command operation to get data in kernel spaceTakashi Sakamoto
In previous commit, a new table for functions with data in kernel space is added to replace current table. This commit changes existent functions to fit the table. These functions are added to the new table and removed from the old table. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-22ALSA: seq: add an alternative way to handle ioctl requestsTakashi Sakamoto
ALSA sequencer is designed with two types of clients; application and kernel. Operations for each ioctl command should handle data in both of user space and kernel space, while current implementation just allows them to handle data in user space. Data in kernel space is handled with change of address limit of running tasks. This commit adds a new table to map ioctl commands to corresponding functions. The functions get data in kernel space. Helper functions to operate kernel and application clients seek entries from the table. Especially, the helper function for application is responsible for coping from user space to kernel space or vise versa. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-08-22ALSA: seq: add documentation for snd_seq_kernel_client_ctlTakashi Sakamoto
This kernel API is used by kernel implementation. Currently, it's used for kernel clients of ALSA sequencer, while it can be used for application clients. The difference is just on address spaces of argument. In short, this kernel API can be available for application client with data in kernel space. This commit adds a document about this. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-06-17ALSA: seq_timer: use monotonic times internallyArnd Bergmann
The sequencer client manager reports timestamps in units of unsigned 32-bit seconds/nanoseconds, but that does not suffer from the y2038 overflow because it stores only the delta since the 'last_update' time was recorded. However, the use of the do_gettimeofday() function is problematic and we have to replace it to avoid the overflow on on 32-bit architectures. This uses 'struct timespec64' to record 'last_update', and changes the code to use monotonic timestamps that do not suffer from leap seconds and settimeofday updates. As a side-effect, the code can now use the timespec64_sub() helper and become more readable and also avoid a multiplication to convert from microseconds to nanoseconds. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-06-15ALSA: seq_oss: Change structure initialisation to C99 styleAmitoj Kaur Chawla
Replace the in order struct initialisation style with explicit field style. The Coccinelle semantic patch used to make this change is as follows: @decl@ identifier i1,fld; type T; field list[n] fs; @@ struct i1 { fs T fld; ...}; @@ identifier decl.i1,i2,decl.fld; expression e; position bad.p, bad.fix; @@ struct i1 i2@p = { ..., + .fld = e - e@fix ,...}; Also, removed some unnecessary comments. Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-04-25ALSA: timer: remove legacy rtctimerAlexandre Belloni
There are no users of rtctimer left. Remove its code as this is the in-kernel user of the legacy PC RTC driver that will hopefully be removed at some point. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-03-08ALSA: seq: Provide card number / PID via sequencer client infoMartin Koegler
rawmidi devices expose the card number via IOCTLs, which allows to find the corresponding device in sysfs. The sequencer provides no identifing data. Chromium works around this issue by scanning rawmidi as well as sequencer devices and matching them by using assumtions, how the kernel register sequencer devices. This changes adds support for exposing the card number for kernel clients as well as the PID for user client. The minor of the API version is changed to distinguish between the zero initialised reserved field and card number 0. [minor coding style fixes by tiwai] Signed-off-by: Martin Koegler <martin.koegler@chello.at> Acked-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-03-01ALSA: seq: oss: Don't drain at closing a clientTakashi Iwai
The OSS sequencer client tries to drain the pending events at releasing. Unfortunately, as spotted by syzkaller fuzzer, this may lead to an unkillable process state when the event has been queued at the far future. Since the process being released can't be signaled any longer, it remains and waits for the echo-back event in that far future. Back to history, the draining feature was implemented at the time we misinterpreted POSIX definition for blocking file operation. Actually, such a behavior is superfluous at release, and we should just release the device as is instead of keeping it up forever. This patch just removes the draining call that may block the release for too long time unexpectedly. BugLink: http://lkml.kernel.org/r/CACT4Y+Y4kD-aBGj37rf-xBw9bH3GMU6P+MYg4W1e-s-paVD2pg@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-02-16ALSA: seq: Fix double port list deletionTakashi Iwai
The commit [7f0973e973cd: ALSA: seq: Fix lockdep warnings due to double mutex locks] split the management of two linked lists (source and destination) into two individual calls for avoiding the AB/BA deadlock. However, this may leave the possible double deletion of one of two lists when the counterpart is being deleted concurrently. It ends up with a list corruption, as revealed by syzkaller fuzzer. This patch fixes it by checking the list emptiness and skipping the deletion and the following process. BugLink: http://lkml.kernel.org/r/CACT4Y+bay9qsrz6dQu31EcGaH9XwfW7o3oBzSQUG9fMszoh=Sg@mail.gmail.com Fixes: 7f0973e973cd ('ALSA: seq: Fix lockdep warnings due to 'double mutex locks) Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-02-15ALSA: seq: Fix leak of pool buffer at concurrent writesTakashi Iwai
When multiple concurrent writes happen on the ALSA sequencer device right after the open, it may try to allocate vmalloc buffer for each write and leak some of them. It's because the presence check and the assignment of the buffer is done outside the spinlock for the pool. The fix is to move the check and the assignment into the spinlock. (The current implementation is suboptimal, as there can be multiple unnecessary vmallocs because the allocation is done before the check in the spinlock. But the pool size is already checked beforehand, so this isn't a big problem; that is, the only possible path is the multiple writes before any pool assignment, and practically seen, the current coverage should be "good enough".) The issue was triggered by syzkaller fuzzer. BugLink: http://lkml.kernel.org/r/CACT4Y+bSzazpXNvtAr=WXaL8hptqjHwqEyFA+VN2AWEx=aurkg@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-02-03ALSA: seq: Fix lockdep warnings due to double mutex locksTakashi Iwai
The port subscription code uses double mutex locks for source and destination ports, and this may become racy once when wrongly set up. It leads to lockdep warning splat, typically triggered by fuzzer like syzkaller, although the actual deadlock hasn't been seen, so far. This patch simplifies the handling by reducing to two single locks, so that no lockdep warning will be trigger any longer. By splitting to two actions, a still-in-progress element shall be added in one list while handling another. For ignoring this element, a new check is added in deliver_to_subscribers(). Along with it, the code to add/remove the subscribers list element was cleaned up and refactored. BugLink: http://lkml.kernel.org/r/CACT4Y+aKQXV7xkBW9hpQbzaDO7LrUvohxWh-UwMxXjDy-yBD=A@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-02-03ALSA: rawmidi: Make snd_rawmidi_transmit() race-freeTakashi Iwai
A kernel WARNING in snd_rawmidi_transmit_ack() is triggered by syzkaller fuzzer: WARNING: CPU: 1 PID: 20739 at sound/core/rawmidi.c:1136 Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82999e2d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81352089>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff813522b9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff84f80bd5>] snd_rawmidi_transmit_ack+0x275/0x400 sound/core/rawmidi.c:1136 [<ffffffff84fdb3c1>] snd_virmidi_output_trigger+0x4b1/0x5a0 sound/core/seq/seq_virmidi.c:163 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff84f87ed9>] snd_rawmidi_kernel_write1+0x549/0x780 sound/core/rawmidi.c:1223 [<ffffffff84f89fd3>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1273 [<ffffffff817b0323>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817b1db7>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817b50a1>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86336c36>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 Also a similar warning is found but in another path: Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff82be2c0d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50 [<ffffffff81355139>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482 [<ffffffff81355369>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515 [<ffffffff8527e69a>] rawmidi_transmit_ack+0x24a/0x3b0 sound/core/rawmidi.c:1133 [<ffffffff8527e851>] snd_rawmidi_transmit_ack+0x51/0x80 sound/core/rawmidi.c:1163 [<ffffffff852d9046>] snd_virmidi_output_trigger+0x2b6/0x570 sound/core/seq/seq_virmidi.c:185 [< inline >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150 [<ffffffff85285a0b>] snd_rawmidi_kernel_write1+0x4bb/0x760 sound/core/rawmidi.c:1252 [<ffffffff85287b73>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1302 [<ffffffff817ba5f3>] __vfs_write+0x113/0x480 fs/read_write.c:528 [<ffffffff817bc087>] vfs_write+0x167/0x4a0 fs/read_write.c:577 [< inline >] SYSC_write fs/read_write.c:624 [<ffffffff817bf371>] SyS_write+0x111/0x220 fs/read_write.c:616 [<ffffffff86660276>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 In the former case, the reason is that virmidi has an open code calling snd_rawmidi_transmit_ack() with the value calculated outside the spinlock. We may use snd_rawmidi_transmit() in a loop just for consuming the input data, but even there, there is a race between snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack(). Similarly in the latter case, it calls snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack() separately without protection, so they are racy as well. The patch tries to address these issues by the following ways: - Introduce the unlocked versions of snd_rawmidi_transmit_peek() and snd_rawmidi_transmit_ack() to be called inside the explicit lock. - Rewrite snd_rawmidi_transmit() to be race-free (the former case). - Make the split calls (the latter case) protected in the rawmidi spin lock. BugLink: http://lkml.kernel.org/r/CACT4Y+YPq1+cYLkadwjWa5XjzF1_Vki1eHnVn-Lm0hzhSpu5PA@mail.gmail.com BugLink: http://lkml.kernel.org/r/CACT4Y+acG4iyphdOZx47Nyq_VHGbpJQK-6xNpiqUjaZYqsXOGw@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-02-01ALSA: seq: Fix yet another races among ALSA timer accessesTakashi Iwai
ALSA sequencer may open/close and control ALSA timer instance dynamically either via sequencer events or direct ioctls. These are done mostly asynchronously, and it may call still some timer action like snd_timer_start() while another is calling snd_timer_close(). Since the instance gets removed by snd_timer_close(), it may lead to a use-after-free. This patch tries to address such a race by protecting each snd_timer_*() call via the existing spinlock and also by avoiding the access to timer during close call. BugLink: http://lkml.kernel.org/r/CACT4Y+Z6RzW5MBr-HUdV-8zwg71WQfKTdPpYGvOeS7v4cyurNQ@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-02-01ALSA: seq: Fix race at closing in virmidi driverTakashi Iwai
The virmidi driver has an open race at closing its assigned rawmidi device, and this may lead to use-after-free in snd_seq_deliver_single_event(). Plug the hole by properly protecting the linked list deletion and calling in the right order in snd_virmidi_input_close(). BugLink: http://lkml.kernel.org/r/CACT4Y+Zd66+w12fNN85-425cVQT=K23kWbhnCEcMB8s3us-Frw@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-01-25ALSA: seq: Degrade the error message for too many opensTakashi Iwai
ALSA OSS sequencer spews a kernel error message ("ALSA: seq_oss: too many applications") when user-space tries to open more than the limit. This means that it can easily fill the log buffer. Since it's merely a normal error, it's safe to suppress it via pr_debug() instead. Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-01-25ALSA: seq: Fix incorrect sanity check at snd_seq_oss_synth_cleanup()Takashi Iwai
ALSA sequencer OSS emulation code has a sanity check for currently opened devices, but there is a thinko there, eventually it spews warnings and skips the operation wrongly like: WARNING: CPU: 1 PID: 7573 at sound/core/seq/oss/seq_oss_synth.c:311 Fix this off-by-one error. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-01-18ALSA: seq: Fix snd_seq_call_port_info_ioctl in compat modeNicolas Boichat
This reverts one hunk of commit ef44a1ec6eee ("ALSA: sound/core: use memdup_user()"), which replaced a number of kmalloc followed by memcpy with memdup calls. In this case, we are copying from a struct snd_seq_port_info32 to a struct snd_seq_port_info, but the latter is 4 bytes longer than the 32-bit version, so we need to separate kmalloc and copy calls. Fixes: ef44a1ec6eee ('ALSA: sound/core: use memdup_user()') Signed-off-by: Nicolas Boichat <drinkcat@chromium.org> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-01-12ALSA: seq: Fix race at timer setup and closeTakashi Iwai
ALSA sequencer code has an open race between the timer setup ioctl and the close of the client. This was triggered by syzkaller fuzzer, and a use-after-free was caught there as a result. This patch papers over it by adding a proper queue->timer_mutex lock around the timer-related calls in the relevant code path. Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2016-01-12ALSA: seq: Fix missing NULL check at remove_events ioctlTakashi Iwai
snd_seq_ioctl_remove_events() calls snd_seq_fifo_clear() unconditionally even if there is no FIFO assigned, and this leads to an Oops due to NULL dereference. The fix is just to add a proper NULL check. Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-12-03ALSA: Fix compat_ioctl handling for OSS emulationsTakashi Iwai
The ALSA PCM, mixer and sequencer OSS emulations provide the 32bit compatible ioctl, but they just call the 64bit native ioctl as is. Although this works in most cases, passing the argument value as-is isn't guaranteed to work on all architectures. We need to convert it via compat_ptr() instead. This patch addresses the missing conversions. Since all relevant ioctls in these functions take the argument as a pointer, we do the pointer conversion in each compat_ioctl and pass it as a 64bit value to the native ioctl. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-11-22ALSA: midi: constify snd_rawmidi_global_ops structuresJulia Lawall
The snd_rawmidi_global_ops structures are never modified, so declare them as const. Done with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-10-09ALSA: seq_oss: fix waitqueue_active without memory barrier in snd-seq-ossKosuke Tatsukawa
snd_seq_oss_readq_put_event() seems to be missing a memory barrier which might cause the waker to not notice the waiter and miss sending a wake_up as in the following figure. snd_seq_oss_readq_put_event snd_seq_oss_readq_wait ------------------------------------------------------------------------ /* wait_event_interruptible_timeout */ /* __wait_event_interruptible_timeout */ /* ___wait_event */ for (;;) { prepare_to_wait_event(&wq, &__wait, state); spin_lock_irqsave(&q->lock, flags); if (waitqueue_active(&q->midi_sleep)) /* The CPU might reorder the test for the waitqueue up here, before prior writes complete */ if ((q->qlen>0 || q->head==q->tail) ... __ret = schedule_timeout(__ret) if (q->qlen >= q->maxlen - 1) { memcpy(&q->q[q->tail], ev, sizeof(*ev)); q->tail = (q->tail + 1) % q->maxlen; q->qlen++; ------------------------------------------------------------------------ There are two other place in sound/core/seq/oss/ which have similar code. The attached patch removes the call to waitqueue_active() leaving just wake_up() behind. This fixes the problem because the call to spin_lock_irqsave() in wake_up() will be an ACQUIRE operation. I found this issue when I was looking through the linux source code for places calling waitqueue_active() before wake_up*(), but without preceding memory barriers, after sending a patch to fix a similar issue in drivers/tty/n_tty.c (Details about the original issue can be found here: https://lkml.org/lkml/2015/9/28/849). Signed-off-by: Kosuke Tatsukawa <tatsu@ab.jp.nec.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-05-29ALSA: core: Fix randconfig build wrt CONFIG_PROC_FSTakashi Iwai
There are a few leftover CONFIG_PROC_FS forgotten to replace with CONFIG_SND_PROC_FS. Fixes: cd6a65036f0e ('ALSA: replace CONFIG_PROC_FS with CONFIG_SND_PROC_FS') Reported-by: Jim Davis <jim.epost@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-05-27ALSA: replace CONFIG_PROC_FS with CONFIG_SND_PROC_FSJie Yang
We may disable proc fs only for sound part, to reduce ALSA memory footprint. So add CONFIG_SND_PROC_FS and replace the old CONFIG_PROC_FSs in alsa code. With sound proc fs disabled, we can save about 9KB memory size on X86_64 platform. Signed-off-by: Jie Yang <yang.jie@intel.com> Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-04-24ALSA: core: Build conditionally and remove superfluous ifdefsTakashi Iwai
Minor cleanups of Makefile to build some codes conditionally so that a few ifdefs can be reduced. Acked-by: Jaroslav Kysela <perex@perex.cz> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-04-24ALSA: core: Don't ignore errors at creating proc filesTakashi Iwai
So far we've ignored the errors at creating proc files in many places. But they should be rather treated seriously. Also, by assuring the error handling, we can get rid of superfluous snd_info_free_entry() calls as they will be removed by the parent in the caller side. This patch fixes the missing error checks and reduces the superfluous free calls. Acked-by: Jaroslav Kysela <perex@perex.cz> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-04-11ALSA: seq: fill client ID in return value of pool operationTakashi Sakamoto
The returned value of 'get/seq client pool' operation has zeroed value for its client ID, against requested client ID. This commit fix the bug by filling it with index value of referred client object. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>