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path: root/sound/core/seq/seq_queue.c
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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>
2017-02-08ALSA: 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>
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>
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>
2015-03-10ALSA: seq: 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>
2014-02-14ALSA: seq: Use standard printk helpersTakashi Iwai
Use the standard pr_xxx() helpers instead of home-baked snd_print*(). 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>
2008-08-13ALSA: Kill snd_assert() in sound/core/*Takashi Iwai
Kill snd_assert() in sound/core/*, either removed or replaced with if () with snd_BUG_ON(). Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jaroslav Kysela <perex@perex.cz>
2008-01-31[ALSA] Remove sound/driver.hTakashi Iwai
This header file exists only for some hacks to adapt alsa-driver tree. It's useless for building in the kernel. Let's move a few lines in it to sound/core.h and remove it. With this patch, sound/driver.h isn't removed but has just a single compile warning to include it. This should be really killed in future. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jaroslav Kysela <perex@perex.cz>
2006-03-22[ALSA] semaphore -> mutex (core part)Ingo Molnar
Semaphore to mutex conversion. The conversion was generated via scripts, and the result was validated automatically via a script as well. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2006-01-03[ALSA] Optimize for config without PROC_FS (seq and oss parts)Takashi Iwai
Modules: ALSA<-OSS emulation,ALSA sequencer,ALSA<-OSS sequencer Optimize the code when compiled without CONFIG_PROC_FS (in seq and oss emulation parts). Signed-off-by: Takashi Iwai <tiwai@suse.de>
2006-01-03[ALSA] Remove xxx_t typedefs: SequencerTakashi Iwai
Modules: ALSA sequencer Remove xxx_t typedefs from the core sequencer codes. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2005-09-12[ALSA] Replace with kzalloc() - seq stuffTakashi Iwai
ALSA sequencer,Instrument layer,ALSA<-OSS sequencer Replace kcalloc(1,..) with kzalloc(). Signed-off-by: Takashi Iwai <tiwai@suse.de>
2005-05-29[ALSA] sound/core/: possible cleanupsAdrian Bunk
PCM Midlevel,ALSA Core,Timer Midlevel,ALSA sequencer,Virtual Midi This patch contains the following possible cleanups: - make needlessly global code static - #if 0 the following unused global functions - remove the following unneeded EXPORT_SYMBOL's Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!