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2016-04-21ALSA: timer: Sync timer deletion at closing the system timerTakashi Iwai1-0/+10
commit f146357f069e71aff8e474c625bcebcd3094b3ab upstream. ALSA timer core framework has no sync point at stopping because it's called inside the spinlock. Thus we need a sync point at close for avoiding the stray timer task. This is simply done by implementing the close callback just calling del_timer_sync(). (It's harmless to call it unconditionally, as the core timer itself cares of the already deleted timer instance.) Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-04-20ALSA: timer: Use mod_timer() for rearming the system timerTakashi Iwai1-2/+2
commit 4a07083ed613644c96c34a7dd2853dc5d7c70902 upstream. ALSA system timer backend stops the timer via del_timer() without sync and leaves del_timer_sync() at the close instead. This is because of the restriction by the design of ALSA timer: namely, the stop callback may be called from the timer handler, and calling the sync shall lead to a hangup. However, this also triggers a kernel BUG() when the timer is rearmed immediately after stopping without sync: kernel BUG at kernel/time/timer.c:966! Call Trace: <IRQ> [<ffffffff8239c94e>] snd_timer_s_start+0x13e/0x1a0 [<ffffffff8239e1f4>] snd_timer_interrupt+0x504/0xec0 [<ffffffff8122fca0>] ? debug_check_no_locks_freed+0x290/0x290 [<ffffffff8239ec64>] snd_timer_s_function+0xb4/0x120 [<ffffffff81296b72>] call_timer_fn+0x162/0x520 [<ffffffff81296add>] ? call_timer_fn+0xcd/0x520 [<ffffffff8239ebb0>] ? snd_timer_interrupt+0xec0/0xec0 .... It's the place where add_timer() checks the pending timer. It's clear that this may happen after the immediate restart without sync in our cases. So, the workaround here is just to use mod_timer() instead of add_timer(). This looks like a band-aid fix, but it's a right move, as snd_timer_interrupt() takes care of the continuous rearm of timer. Reported-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-04-11ALSA: seq: Fix leak of pool buffer at concurrent writesTakashi Iwai1-6/+9
commit d99a36f4728fcbcc501b78447f625bdcce15b842 upstream. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-04-11ALSA: rawmidi: Make snd_rawmidi_transmit() race-freeTakashi Iwai2-31/+84
commit 06ab30034ed9c200a570ab13c017bde248ddb2a6 upstream. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-03-07ALSA: timer: Fix broken compat timer user status ioctlTakashi Iwai1-2/+3
commit 3a72494ac2a3bd229db941d51e7efe2f6ccd947b upstream. The timer user status compat ioctl returned the bogus struct used for 64bit architectures instead of the 32bit one. This patch addresses it to return the proper struct. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-03-07ALSA: seq: oss: Don't drain at closing a clientTakashi Iwai3-20/+0
commit 197b958c1e76a575d77038cc98b4bebc2134279f upstream. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-03-07ALSA: timer: Fix ioctls for X32 ABITakashi Iwai1-0/+13
commit b24e7ad1fdc22177eb3e51584e1cfcb45d818488 upstream. X32 ABI takes the 64bit timespec, thus the timer user status ioctl becomes incompatible with IA32. This results in NOTTY error when the ioctl is issued. Meanwhile, this struct in X32 is essentially identical with the one in X86-64, so we can just bypassing to the existing code for this specific compat ioctl. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-03-07ALSA: rawmidi: Fix ioctls X32 ABITakashi Iwai1-0/+53
commit 2251fbbc1539f05b0b206b37a602d5776be37252 upstream. Like the previous fixes for ctl and PCM, we need a fix for incompatible X32 ABI regarding the rawmidi: namely, struct snd_rawmidi_status has the timespec, and the size and the alignment on X32 differ from IA32. This patch fixes the incompatible ioctl for X32. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-03-07ALSA: ctl: Fix ioctls for X32 ABITakashi Iwai1-16/+74
commit 6236d8bb2afcfe71b88ecea554e0dc638090a45f upstream. The X32 ABI takes the same alignment like x86-64, and this may result in the incompatible struct size from ia32. Unfortunately, we hit this in some control ABI: struct snd_ctl_elem_value differs between them due to the position of 64bit variable array. This ends up with the unknown ioctl (ENOTTY) error. The fix is to add the compat entries for the new aligned struct. Reported-and-tested-by: Steven Newbury <steve@snewbury.org.uk> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-02-24ALSA: seq: Fix double port list deletionTakashi Iwai1-5/+8
commit 13d5e5d4725c64ec06040d636832e78453f477b7 upstream. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-02-15ALSA: timer: Fix race between stop and interruptTakashi Iwai1-0/+4
commit ed8b1d6d2c741ab26d60d499d7fbb7ac801f0f51 upstream. A slave timer element also unlinks at snd_timer_stop() but it takes only slave_active_lock. When a slave is assigned to a master, however, this may become a race against the master's interrupt handling, eventually resulting in a list corruption. The actual bug could be seen with a syzkaller fuzzer test case in BugLink below. As a fix, we need to take timeri->timer->lock when timer isn't NULL, i.e. assigned to a master, while the assignment to a master itself is protected by slave_active_lock. BugLink: http://lkml.kernel.org/r/CACT4Y+Y_Bm+7epAb=8Wi=AaWd+DYS7qawX52qxdCfOfY49vozQ@mail.gmail.com Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-02-15ALSA: timer: Fix wrong instance passed to slave callbacksTakashi Iwai1-1/+1
commit 117159f0b9d392fb433a7871426fad50317f06f7 upstream. In snd_timer_notify1(), the wrong timer instance was passed for slave ccallback function. This leads to the access to the wrong data when an incompatible master is handled (e.g. the master is the sequencer timer and the slave is a user timer), as spotted by syzkaller fuzzer. This patch fixes that wrong assignment. BugLink: http://lkml.kernel.org/r/CACT4Y+Y_Bm+7epAb=8Wi=AaWd+DYS7qawX52qxdCfOfY49vozQ@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-02-15ALSA: timer: Fix link corruption due to double start or stopTakashi Iwai1-2/+28
commit f784beb75ce82f4136f8a0960d3ee872f7109e09 upstream. Although ALSA timer code got hardening for races, it still causes use-after-free error. This is however rather a corrupted linked list, not actually the concurrent accesses. Namely, when timer start is triggered twice, list_add_tail() is called twice, too. This ends up with the link corruption and triggers KASAN error. The simplest fix would be replacing list_add_tail() with list_move_tail(), but fundamentally it's the problem that we don't check the double start/stop correctly. So, the right fix here is to add the proper checks to snd_timer_start() and snd_timer_stop() (and their variants). BugLink: http://lkml.kernel.org/r/CACT4Y+ZyPRoMQjmawbvmCEDrkBD2BQuH7R09=eOkf5ESK8kJAw@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-02-15ALSA: timer: Fix leftover link at closingTakashi Iwai1-2/+2
commit 094fd3be87b0f102589e2d5c3fa5d06b7e20496d upstream. In ALSA timer core, the active timer instance is managed in active_list linked list. Each element is added / removed dynamically at timer start, stop and in timer interrupt. The problem is that snd_timer_interrupt() has a thinko and leaves the element in active_list when it's the last opened element. This eventually leads to list corruption or use-after-free error. This hasn't been revealed because we used to delete the list forcibly in snd_timer_stop() in the past. However, the recent fix avoids the double-stop behavior (in commit [f784beb75ce8: ALSA: timer: Fix link corruption due to double start or stop]), and this leak hits reality. This patch fixes the link management in snd_timer_interrupt(). Now it simply unlinks no matter which stream is. BugLink: http://lkml.kernel.org/r/CACT4Y+Yy2aukHP-EDp8-ziNqNNmb-NTf=jDWXMP7jB8HDa2vng@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-02-15ALSA: timer: Code cleanupTakashi Iwai1-17/+11
commit c3b1681375dc6e71d89a3ae00cc3ce9e775a8917 upstream. This is a minor code cleanup without any functional changes: - Kill keep_flag argument from _snd_timer_stop(), as all callers pass only it false. - Remove redundant NULL check in _snd_timer_stop(). Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-02-15ALSA: seq: Fix lockdep warnings due to double mutex locksTakashi Iwai2-103/+133
commit 7f0973e973cd74aa40747c9d38844560cd184ee8 upstream. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-02-15ALSA: seq: Fix race at closing in virmidi driverTakashi Iwai1-1/+5
commit 2d1b5c08366acd46c35a2e9aba5d650cb5bf5c19 upstream. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-02-15ALSA: seq: Fix yet another races among ALSA timer accessesTakashi Iwai1-20/+67
commit 2cdc7b636d55cbcf42e1e6c8accd85e62d3e9ae8 upstream. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-02-15ALSA: pcm: Fix potential deadlock in OSS emulationTakashi Iwai1-6/+15
commit b248371628aad599a48540962f6b85a21a8a0c3f upstream. There are potential deadlocks in PCM OSS emulation code while accessing read/write and mmap concurrently. This comes from the infamous mmap_sem usage in copy_from/to_user(). Namely, snd_pcm_oss_write() -> &runtime->oss.params_lock -> copy_to_user() -> &mm->mmap_sem mmap() -> &mm->mmap_sem -> snd_pcm_oss_mmap() -> &runtime->oss.params_lock Since we can't avoid taking params_lock from mmap code path, use trylock variant and aborts with -EAGAIN as a workaround of this AB/BA deadlock. BugLink: http://lkml.kernel.org/r/CACT4Y+bVrBKDG0G2_AcUgUQa+X91VKTeS4v+wN7BSHwHtqn3kQ@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-02-15ALSA: rawmidi: Fix race at copying & updating the positionTakashi Iwai1-12/+22
commit 81f577542af15640cbcb6ef68baa4caa610cbbfc upstream. The rawmidi read and write functions manage runtime stream status such as runtime->appl_ptr and runtime->avail. These point where to copy the new data and how many bytes have been copied (or to be read). The problem is that rawmidi read/write call copy_from_user() or copy_to_user(), and the runtime spinlock is temporarily unlocked and relocked while copying user-space. Since the current code advances and updates the runtime status after the spin unlock/relock, the copy and the update may be asynchronous, and eventually runtime->avail might go to a negative value when many concurrent accesses are done. This may lead to memory corruption in the end. For fixing this race, in this patch, the status update code is performed in the same lock before the temporary unlock. Also, the spinlock is now taken more widely in snd_rawmidi_kernel_read1() for protecting more properly during the whole operation. BugLink: http://lkml.kernel.org/r/CACT4Y+b-dCmNf1GpgPKfDO0ih+uZCL2JV4__j-r1kdhPLSgQCQ@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-02-15ALSA: rawmidi: Remove kernel WARNING for NULL user-space buffer checkTakashi Iwai1-1/+1
commit cc85f7a634cfaf9f0713c6aa06d08817424db37a upstream. NULL user-space buffer can be passed even in a normal path, thus it's not good to spew a kernel warning with stack trace at each time. Just drop snd_BUG_ON() macro usage there. BugLink: http://lkml.kernel.org/r/CACT4Y+YfVJ3L+q0i-4vyQVyyPD7V=OMX0PWPi29x9Bo3QaBLdw@mail.gmail.com Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-02-15ALSA: seq: Fix incorrect sanity check at snd_seq_oss_synth_cleanup()Takashi Iwai1-1/+1
commit 599151336638d57b98d92338aa59c048e3a3e97d upstream. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-02-15ALSA: compress: Disable GET_CODEC_CAPS ioctl for some architecturesTakashi Iwai1-0/+11
commit 462b3f161beb62eeb290f4ec52f5ead29a2f8ac7 upstream. Some architectures like PowerPC can handle the maximum struct size in an ioctl only up to 13 bits, and struct snd_compr_codec_caps used by SNDRV_COMPRESS_GET_CODEC_CAPS ioctl overflows this limit. This problem was revealed recently by a powerpc change, as it's now treated as a fatal build error. This patch is a stop-gap for that: for architectures with less than 14 bit ioctl struct size, get rid of the handling of the relevant ioctl. We should provide an alternative equivalent ioctl code later, but for now just paper over it. Luckily, the compress API hasn't been used on such architectures, so the impact must be effectively zero. Reviewed-by: Mark Brown <broonie@kernel.org> Acked-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-01-27ALSA: control: Avoid kernel warnings from tlv ioctl with numid 0Takashi Iwai1-0/+2
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: Jiri Slaby <jslaby@suse.cz>
2016-01-27ALSA: hrtimer: Fix stall by hrtimer_cancel()Takashi Iwai1-1/+2
commit 2ba1fe7a06d3624f9a7586d672b55f08f7c670f3 upstream. hrtimer_cancel() waits for the completion from the callback, thus it must not be called inside the callback itself. This was already a problem in the past with ALSA hrtimer driver, and the early commit [fcfdebe70759: ALSA: hrtimer - Fix lock-up] tried to address it. However, the previous fix is still insufficient: it may still cause a lockup when the ALSA timer instance reprograms itself in its callback. Then it invokes the start function even in snd_timer_interrupt() that is called in hrtimer callback itself, results in a CPU stall. This is no hypothetical problem but actually triggered by syzkaller fuzzer. This patch tries to fix the issue again. Now we call hrtimer_try_to_cancel() at both start and stop functions so that it won't fall into a deadlock, yet giving some chance to cancel the queue if the functions have been called outside the callback. The proper hrtimer_cancel() is called in anyway at closing, so this should be enough. Reported-and-tested-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-01-27ALSA: pcm: Fix snd_pcm_hw_params struct copy in compat modeNicolas Boichat1-4/+9
commit 43c54b8c7cfe22f868a751ba8a59abf1724160b1 upstream. 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_pcm_hw_params32 to a struct snd_pcm_hw_params, but the latter is 4 bytes longer than the 32-bit version, so we need to separate kmalloc and copy calls. This actually leads to an out-of-bounds memory access later on in sound/soc/soc-pcm.c:soc_pcm_hw_params() (detected using KASan). Fixes: ef44a1ec6eee ('ALSA: sound/core: use memdup_user()') Signed-off-by: Nicolas Boichat <drinkcat@chromium.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-01-27ALSA: seq: Fix snd_seq_call_port_info_ioctl in compat modeNicolas Boichat1-4/+5
commit 9586495dc3011a80602329094e746dbce16cb1f1 upstream. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-01-27ALSA: timer: Fix double unlink of active_listTakashi Iwai1-1/+1
commit ee8413b01045c74340aa13ad5bdf905de32be736 upstream. ALSA timer instance object has a couple of linked lists and they are unlinked unconditionally at snd_timer_stop(). Meanwhile snd_timer_interrupt() unlinks it, but it calls list_del() which leaves the element list itself unchanged. This ends up with unlinking twice, and it was caught by syzkaller fuzzer. The fix is to use list_del_init() variant properly there, too. Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-01-27ALSA: timer: Fix race among timer ioctlsTakashi Iwai1-13/+19
commit af368027a49a751d6ff4ee9e3f9961f35bb4fede upstream. ALSA timer ioctls have an open race and this may lead to a use-after-free of timer instance object. A simplistic fix is to make each ioctl exclusive. We have already tread_sem for controlling the tread, and extend this as a global mutex to be applied to each ioctl. The downside is, of course, the worse concurrency. But these ioctls aren't to be parallel accessible, in anyway, so it should be fine to serialize there. Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-01-27ALSA: timer: Harden slave timer list handlingTakashi Iwai1-4/+14
commit b5a663aa426f4884c71cd8580adae73f33570f0d upstream. A slave timer instance might be still accessible in a racy way while operating the master instance as it lacks of locking. Since the master operation is mostly protected with timer->lock, we should cope with it while changing the slave instance, too. Also, some linked lists (active_list and ack_list) of slave instances aren't unlinked immediately at stopping or closing, and this may lead to unexpected accesses. This patch tries to address these issues. It adds spin lock of timer->lock (either from master or slave, which is equivalent) in a few places. For avoiding a deadlock, we ensure that the global slave_active_lock is always locked at first before each timer lock. Also, ack and active_list of slave instances are properly unlinked at snd_timer_stop() and snd_timer_close(). Last but not least, remove the superfluous call of _snd_timer_stop() at removing slave links. This is a noop, and calling it may confuse readers wrt locking. Further cleanup will follow in a later patch. Actually we've got reports of use-after-free by syzkaller fuzzer, and this hopefully fixes these issues. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-01-27ALSA: seq: Fix race at timer setup and closeTakashi Iwai1-0/+2
commit 3567eb6af614dac436c4b16a8d426f9faed639b3 upstream. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-01-27ALSA: seq: Fix missing NULL check at remove_events ioctlTakashi Iwai1-1/+1
commit 030e2c78d3a91dd0d27fef37e91950dde333eba1 upstream. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-04-09ALSA: control: Add sanity checks for user ctl id name stringTakashi Iwai1-0/+4
commit be3bb8236db2d0fcd705062ae2e2a9d75131222f upstream. 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. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-03-12ALSA: pcm: Don't leave PREPARED state after drainingTakashi Iwai1-0/+2
commit 70372a7566b5e552dbe48abdac08c275081d8558 upstream. When a PCM draining is performed to an empty stream that has been already in PREPARED state, the current code just ignores and leaves as it is, although the drain is supposed to set all such streams to SETUP state. This patch covers that overlooked case. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-02-08ALSA: seq-dummy: remove deadlock-causing events on closeClemens Ladisch1-31/+0
commit 0767e95bb96d7fdddcd590fb809e6975d93aebc5 upstream. When the last subscriber to a "Through" port has been removed, the subscribed destination ports might still be active, so it would be wrong to send "all sounds off" and "reset controller" events to them. The proper place for such a shutdown would be the closing of the actual MIDI port (and close_substream() in rawmidi.c already can do this). This also fixes a deadlock when dummy_unuse() tries to send events to its own port that is already locked because it is being freed. Reported-by: Peter Billam <peter@www.pjb.com.au> Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-11-13ALSA: pcm: Zero-clear reserved fields of PCM status ioctl in compat modeTakashi Iwai1-0/+2
commit 317168d0c766defd14b3d0e9c2c4a9a258b803ee upstream. In compat mode, we copy each field of snd_pcm_status struct but don't touch the reserved fields, and this leaves uninitialized values there. Meanwhile the native ioctl does zero-clear the whole structure, so we should follow the same rule in compat mode, too. Reported-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-10-31ALSA: pcm: use the same dma mmap codepath both for arm and arm64Anatol Pomozov1-1/+1
commit a011e213f3700233ed2a676f1ef0a74a052d7162 upstream. This avoids following kernel crash when try to playback on arm64 [ 107.497203] [<ffffffc00046b310>] snd_pcm_mmap_data_fault+0x90/0xd4 [ 107.503405] [<ffffffc0001541ac>] __do_fault+0xb0/0x498 [ 107.508565] [<ffffffc0001576a0>] handle_mm_fault+0x224/0x7b0 [ 107.514246] [<ffffffc000092640>] do_page_fault+0x11c/0x310 [ 107.519738] [<ffffffc000081100>] do_mem_abort+0x38/0x98 Tested: backported to 3.14 and tried to playback on arm64 machine Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-10-13ALSA: pcm: fix fifo_size frame calculationClemens Ladisch1-3/+5
commit a9960e6a293e6fc3ed414643bb4e4106272e4d0a upstream. The calculated frame size was wrong because snd_pcm_format_physical_width() actually returns the number of bits, not bytes. Use snd_pcm_format_size() instead, which not only returns bytes, but also simplifies the calculation. Fixes: 8bea869c5e56 ("ALSA: PCM midlevel: improve fifo_size handling") Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-10-13ALSA: core: fix buffer overflow in snd_info_get_line()Clemens Ladisch1-2/+2
commit ddc64b278a4dda052390b3de1b551e59acdff105 upstream. snd_info_get_line() documents that its last parameter must be one less than the buffer size, but this API design guarantees that (literally) every caller gets it wrong. Just change this parameter to have its obvious meaning. Reported-by: Tommi Rantala <tt.rantala@gmail.com> Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-07-02ALSA: control: Make sure that id->index does not overflowLars-Peter Clausen1-0/+3
commit 883a1d49f0d77d30012f114b2e19fc141beb3e8e upstream. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-07-02ALSA: control: Handle numid overflowLars-Peter Clausen1-0/+4
commit ac902c112d90a89e59916f751c2745f4dbdbb4bd upstream. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-07-02ALSA: control: Don't access controls outside of protected regionsLars-Peter Clausen1-5/+10
commit fd9f26e4eca5d08a27d12c0933fceef76ed9663d upstream. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-07-02ALSA: control: Fix replacing user controlsLars-Peter Clausen1-16/+9
commit 82262a46627bebb0febcc26664746c25cef08563 upstream. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-07-02ALSA: control: Protect user controls against concurrent accessLars-Peter Clausen2-6/+26
commit 07f4d9d74a04aa7c72c5dae0ef97565f28f17b92 upstream. 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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-03-31ALSA: compress: Pass through return value of open ops callbackCharles Keepax1-1/+1
commit 749d32237bf39e6576dd95bfdf24e4378e51716c upstream. The snd_compr_open function would always return 0 even if the compressed ops open function failed, obviously this is incorrect. Looks like this was introduced by a small typo in: commit a0830dbd4e42b38aefdf3fb61ba5019a1a99ea85 ALSA: Add a reference counter to card instance This patch returns the value from the compressed op as it should. Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Acked-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-02-06ALSA: bits vs bytes bug in snd_card_create()Dan Carpenter1-2/+2
commit 4c3773eda49c872a3034382f8ec3080002e715bf upstream. The test here is intended intended to prevent shift wrapping bugs when we do "1U << idx2". We should consider the number of bits in a u32 instead of the number of bytes. [fix another chunk similarly by tiwai] Fixes: 7bb2491b35a2 ('ALSA: Add kconfig to specify the max card numbers') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-10ALSA: Add SNDRV_PCM_STATE_PAUSED case in wait_for_avail functionJongHo Kim1-0/+2
commit ed697e1aaf7237b1a62af39f64463b05c262808d upstream. When the process is sleeping at the SNDRV_PCM_STATE_PAUSED state from the wait_for_avail function, the sleep process will be woken by timeout(10 seconds). Even if the sleep process wake up by timeout, by this patch, the process will continue with sleep and wait for the other state. Signed-off-by: JongHo Kim <furmuwon@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29ALSA: compress: fix drain calls blocking other compress functions (v6)Vinod Koul1-12/+19
commit f44f2a5417b2968a8724b352cc0b2545a6bcb1f4 upstream. The drain and drain_notify callback were blocked by low level driver until the draining was complete. Due to this being invoked with big fat mutex held, others ops like reading timestamp, calling pause, drop were blocked. So to fix this we add a new snd_compr_drain_notify() API. This would be required to be invoked by low level driver when drain or partial drain has been completed by the DSP. Thus we make the drain and partial_drain callback as non blocking and driver returns immediately after notifying DSP. The waiting is done while releasing the lock so that other ops can go ahead. [ The commit 917f4b5cba78 was wrongly applied from the preliminary patch. This commit corrects to the final version. Sorry for inconvenience! -- tiwai ] Signed-off-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29ALSA: compress: fix drain calls blocking other compress functionsVinod Koul1-3/+38
commit 917f4b5cba78980a527098a910d94139d3e82c8d upstream. The drain and drain_notify callback were blocked by low level driver untill the draining was complete. Due to this being invoked with big fat mutex held, others ops like reading timestamp, calling pause, drop were blocked. So to fix this we add a new snd_compr_drain_notify() API. This would be required to be invoked by low level driver when drain or partial drain has been completed by the DSP. Thus we make the drain and partial_drain callback as non blocking and driver returns immediately after notifying DSP. The waiting is done while relasing the lock so that other ops can go ahead. Signed-off-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-31ALSA: fix oops in snd_pcm_info() caused by ASoC DPCMRussell King1-0/+4
Unable to handle kernel NULL pointer dereference at virtual address 00000008 pgd = d5300000 [00000008] *pgd=0d265831, *pte=00000000, *ppte=00000000 Internal error: Oops: 17 [#1] PREEMPT ARM CPU: 0 PID: 2295 Comm: vlc Not tainted 3.11.0+ #755 task: dee74800 ti: e213c000 task.ti: e213c000 PC is at snd_pcm_info+0xc8/0xd8 LR is at 0x30232065 pc : [<c031b52c>] lr : [<30232065>] psr: a0070013 sp : e213dea8 ip : d81cb0d0 fp : c05f7678 r10: c05f7770 r9 : fffffdfd r8 : 00000000 r7 : d8a968a8 r6 : d8a96800 r5 : d8a96200 r4 : d81cb000 r3 : 00000000 r2 : d81cb000 r1 : 00000001 r0 : d8a96200 Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 10c5387d Table: 15300019 DAC: 00000015 Process vlc (pid: 2295, stack limit = 0xe213c248) [<c031b52c>] (snd_pcm_info) from [<c031b570>] (snd_pcm_info_user+0x34/0x9c) [<c031b570>] (snd_pcm_info_user) from [<c03164a4>] (snd_pcm_control_ioctl+0x274/0x280) [<c03164a4>] (snd_pcm_control_ioctl) from [<c0311458>] (snd_ctl_ioctl+0xc0/0x55c) [<c0311458>] (snd_ctl_ioctl) from [<c00eca84>] (do_vfs_ioctl+0x80/0x31c) [<c00eca84>] (do_vfs_ioctl) from [<c00ecd5c>] (SyS_ioctl+0x3c/0x60) [<c00ecd5c>] (SyS_ioctl) from [<c000e500>] (ret_fast_syscall+0x0/0x48) Code: e1a00005 e59530dc e3a01001 e1a02004 (e5933008) ---[ end trace cb3d9bdb8dfefb3c ]--- This is provoked when the ASoC front end is open along with its backend, (which causes the backend to have a runtime assigned to it) and then the SNDRV_CTL_IOCTL_PCM_INFO is requested for the (visible) backend device. Resolve this by ensuring that ASoC internal backend devices are not visible to userspace, just as the commentry for snd_pcm_new_internal() says it should be. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Mark Brown <broonie@linaro.org> Cc: <stable@vger.kernel.org> [v3.4+] Signed-off-by: Takashi Iwai <tiwai@suse.de>
generated by cgit v1.2.3 (git 2.39.0) at 2025-09-30 22:37:50 +0300