possible deadlock in snd_pcm_period_elapsed

From: syzbot
Date: Wed Oct 14 2020 - 08:02:19 EST


Hello,

syzbot found the following issue on:

HEAD commit: 029f56db Merge tag 'x86_asm_for_v5.10' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1366d607900000
kernel config: https://syzkaller.appspot.com/x/.config?x=c5327fbeef7650a
dashboard link: https://syzkaller.appspot.com/bug?extid=9e4ce89a893162de3148
compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9e4ce89a893162de3148@xxxxxxxxxxxxxxxxxxxxxxxxx

========================================================
WARNING: possible irq lock inversion dependency detected
5.9.0-syzkaller #0 Not tainted
--------------------------------------------------------
swapper/0/0 just changed the state of lock:
ffff88809a617108 (&group->lock){..-.}-{2:2}, at: snd_pcm_period_elapsed+0x2c/0x210 sound/core/pcm_lib.c:1799
but this lock took another, SOFTIRQ-READ-unsafe lock in the past:
(&card->ctl_files_rwlock){.+.+}-{2:2}


and interrupts could create inverse lock ordering between them.


other info that might help us debug this:
Possible interrupt unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&card->ctl_files_rwlock);
local_irq_disable();
lock(&group->lock);
lock(&card->ctl_files_rwlock);
<Interrupt>
lock(&group->lock);

*** DEADLOCK ***

1 lock held by swapper/0/0:
#0: ffffc90000007db0 ((&dpcm->timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:45 [inline]
#0: ffffc90000007db0 ((&dpcm->timer)){+.-.}-{0:0}, at: call_timer_fn+0x57/0x160 kernel/time/timer.c:1405

the shortest dependencies between 2nd lock and 1st lock:
-> (&card->ctl_files_rwlock){.+.+}-{2:2} {
HARDIRQ-ON-R at:
lock_acquire+0x160/0x710 kernel/locking/lockdep.c:5442
__raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
_raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223
snd_ctl_notify+0x86/0x550 sound/core/control.c:153
__snd_ctl_add_replace+0x582/0x8a0 sound/core/control.c:382
snd_ctl_add_replace sound/core/control.c:399 [inline]
snd_ctl_add+0x6e/0x110 sound/core/control.c:426
snd_card_dummy_new_mixer sound/drivers/dummy.c:885 [inline]
snd_dummy_probe+0xb9e/0x1000 sound/drivers/dummy.c:1080
platform_drv_probe+0xcd/0x150 drivers/base/platform.c:747
really_probe+0x753/0x1110 drivers/base/dd.c:557
driver_probe_device+0x106/0x1a0 drivers/base/dd.c:738
bus_for_each_drv+0x108/0x170 drivers/base/bus.c:431
__device_attach+0x262/0x3f0 drivers/base/dd.c:912
bus_probe_device+0xb8/0x1f0 drivers/base/bus.c:491
device_add+0x1630/0x19b0 drivers/base/core.c:2926
platform_device_add+0x4ad/0x6e0 drivers/base/platform.c:597
platform_device_register_full+0x448/0x530 drivers/base/platform.c:720
platform_device_register_resndata include/linux/platform_device.h:131 [inline]
platform_device_register_simple include/linux/platform_device.h:160 [inline]
alsa_card_dummy_init+0x1b3/0x398 sound/drivers/dummy.c:1168
do_one_initcall+0x14b/0x350 init/main.c:1205
do_initcall_level+0x101/0x14c init/main.c:1278
do_initcalls+0x59/0x9b init/main.c:1294
kernel_init_freeable+0x356/0x474 init/main.c:1514
kernel_init+0xd/0x290 init/main.c:1403
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
SOFTIRQ-ON-R at:
lock_acquire+0x160/0x710 kernel/locking/lockdep.c:5442
__raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
_raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223
snd_ctl_notify+0x86/0x550 sound/core/control.c:153
__snd_ctl_add_replace+0x582/0x8a0 sound/core/control.c:382
snd_ctl_add_replace sound/core/control.c:399 [inline]
snd_ctl_add+0x6e/0x110 sound/core/control.c:426
snd_card_dummy_new_mixer sound/drivers/dummy.c:885 [inline]
snd_dummy_probe+0xb9e/0x1000 sound/drivers/dummy.c:1080
platform_drv_probe+0xcd/0x150 drivers/base/platform.c:747
really_probe+0x753/0x1110 drivers/base/dd.c:557
driver_probe_device+0x106/0x1a0 drivers/base/dd.c:738
bus_for_each_drv+0x108/0x170 drivers/base/bus.c:431
__device_attach+0x262/0x3f0 drivers/base/dd.c:912
bus_probe_device+0xb8/0x1f0 drivers/base/bus.c:491
device_add+0x1630/0x19b0 drivers/base/core.c:2926
platform_device_add+0x4ad/0x6e0 drivers/base/platform.c:597
platform_device_register_full+0x448/0x530 drivers/base/platform.c:720
platform_device_register_resndata include/linux/platform_device.h:131 [inline]
platform_device_register_simple include/linux/platform_device.h:160 [inline]
alsa_card_dummy_init+0x1b3/0x398 sound/drivers/dummy.c:1168
do_one_initcall+0x14b/0x350 init/main.c:1205
do_initcall_level+0x101/0x14c init/main.c:1278
do_initcalls+0x59/0x9b init/main.c:1294
kernel_init_freeable+0x356/0x474 init/main.c:1514
kernel_init+0xd/0x290 init/main.c:1403
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
INITIAL READ USE at:
lock_acquire+0x160/0x710 kernel/locking/lockdep.c:5442
__raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
_raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223
snd_ctl_notify+0x86/0x550 sound/core/control.c:153
__snd_ctl_add_replace+0x582/0x8a0 sound/core/control.c:382
snd_ctl_add_replace sound/core/control.c:399 [inline]
snd_ctl_add+0x6e/0x110 sound/core/control.c:426
snd_card_dummy_new_mixer sound/drivers/dummy.c:885 [inline]
snd_dummy_probe+0xb9e/0x1000 sound/drivers/dummy.c:1080
platform_drv_probe+0xcd/0x150 drivers/base/platform.c:747
really_probe+0x753/0x1110 drivers/base/dd.c:557
driver_probe_device+0x106/0x1a0 drivers/base/dd.c:738
bus_for_each_drv+0x108/0x170 drivers/base/bus.c:431
__device_attach+0x262/0x3f0 drivers/base/dd.c:912
bus_probe_device+0xb8/0x1f0 drivers/base/bus.c:491
device_add+0x1630/0x19b0 drivers/base/core.c:2926
platform_device_add+0x4ad/0x6e0 drivers/base/platform.c:597
platform_device_register_full+0x448/0x530 drivers/base/platform.c:720
platform_device_register_resndata include/linux/platform_device.h:131 [inline]
platform_device_register_simple include/linux/platform_device.h:160 [inline]
alsa_card_dummy_init+0x1b3/0x398 sound/drivers/dummy.c:1168
do_one_initcall+0x14b/0x350 init/main.c:1205
do_initcall_level+0x101/0x14c init/main.c:1278
do_initcalls+0x59/0x9b init/main.c:1294
kernel_init_freeable+0x356/0x474 init/main.c:1514
kernel_init+0xd/0x290 init/main.c:1403
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
}
... key at: [<ffffffff8c877e10>] snd_card_new.__key.3+0x0/0x10
... acquired at:
lock_acquire+0x160/0x710 kernel/locking/lockdep.c:5442
__raw_read_lock include/linux/rwlock_api_smp.h:149 [inline]
_raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223
snd_ctl_notify+0x86/0x550 sound/core/control.c:153
loopback_check_format sound/drivers/aloop.c:358 [inline]
loopback_trigger+0xc40/0x1500 sound/drivers/aloop.c:387
snd_pcm_do_start sound/core/pcm_native.c:1350 [inline]
snd_pcm_action_single sound/core/pcm_native.c:1207 [inline]
snd_pcm_action sound/core/pcm_native.c:1290 [inline]
snd_pcm_start+0x471/0x6c0 sound/core/pcm_native.c:1391
__snd_pcm_lib_xfer+0xf73/0x1320 sound/core/pcm_lib.c:2247
snd_pcm_oss_write3+0x209/0x330 sound/core/oss/pcm_oss.c:1221
snd_pcm_plug_write_transfer+0x28b/0x490 sound/core/oss/pcm_plugin.c:624
snd_pcm_oss_write2+0x156/0x370 sound/core/oss/pcm_oss.c:1353
snd_pcm_oss_write1 sound/core/oss/pcm_oss.c:1419 [inline]
snd_pcm_oss_write+0x911/0xd70 sound/core/oss/pcm_oss.c:2765
vfs_write+0x2dd/0xd20 fs/read_write.c:584
ksys_write+0x11b/0x220 fs/read_write.c:639
do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

-> (&group->lock){..-.}-{2:2} {
IN-SOFTIRQ-W at:
lock_acquire+0x160/0x710 kernel/locking/lockdep.c:5442
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xaa/0xd0 kernel/locking/spinlock.c:159
snd_pcm_period_elapsed+0x2c/0x210 sound/core/pcm_lib.c:1799
call_timer_fn+0x91/0x160 kernel/time/timer.c:1415
expire_timers kernel/time/timer.c:1460 [inline]
__run_timers+0x65e/0x830 kernel/time/timer.c:1757
run_timer_softirq+0x46/0x80 kernel/time/timer.c:1770
__do_softirq+0x256/0x6e0 kernel/softirq.c:298
asm_call_irq_on_stack+0xf/0x20
__run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
do_softirq_own_stack+0x9a/0xf0 arch/x86/kernel/irq_64.c:77
invoke_softirq kernel/softirq.c:393 [inline]
__irq_exit_rcu+0x21f/0x230 kernel/softirq.c:423
irq_exit_rcu+0x5/0x20 kernel/softirq.c:435
sysvec_apic_timer_interrupt+0xe0/0xf0 arch/x86/kernel/apic/apic.c:1091
asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581
native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60
arch_safe_halt arch/x86/include/asm/paravirt.h:150 [inline]
acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline]
acpi_idle_do_entry+0xde/0x2d0 drivers/acpi/processor_idle.c:517
acpi_idle_enter+0x2fa/0x440 drivers/acpi/processor_idle.c:648
cpuidle_enter_state+0x38a/0x980 drivers/cpuidle/cpuidle.c:237
cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:350
call_cpuidle kernel/sched/idle.c:132 [inline]
cpuidle_idle_call kernel/sched/idle.c:213 [inline]
do_idle+0x4a7/0x650 kernel/sched/idle.c:273
cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:369
start_kernel+0x4b0/0x57c init/main.c:1049
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243
INITIAL USE at:
lock_acquire+0x160/0x710 kernel/locking/lockdep.c:5442
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
_raw_spin_lock_irq+0xa6/0xc0 kernel/locking/spinlock.c:167
spin_lock_irq include/linux/spinlock.h:379 [inline]
snd_pcm_group_lock_irq sound/core/pcm_native.c:97 [inline]
snd_pcm_stream_lock_irq sound/core/pcm_native.c:136 [inline]
snd_pcm_hw_params+0xca/0x16b0 sound/core/pcm_native.c:672
snd_pcm_oss_change_params_locked+0x25e0/0x4410 sound/core/oss/pcm_oss.c:941
snd_pcm_oss_make_ready_locked sound/core/oss/pcm_oss.c:1166 [inline]
snd_pcm_oss_write1 sound/core/oss/pcm_oss.c:1384 [inline]
snd_pcm_oss_write+0x269/0xd70 sound/core/oss/pcm_oss.c:2765
vfs_write+0x2dd/0xd20 fs/read_write.c:584
ksys_write+0x11b/0x220 fs/read_write.c:639
do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
}
... key at: [<ffffffff8c8794a8>] snd_pcm_group_init.__key+0x0/0x10
... acquired at:
mark_usage kernel/locking/lockdep.c:4305 [inline]
__lock_acquire+0xa67/0x2bd0 kernel/locking/lockdep.c:4791
lock_acquire+0x160/0x710 kernel/locking/lockdep.c:5442
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xaa/0xd0 kernel/locking/spinlock.c:159
snd_pcm_period_elapsed+0x2c/0x210 sound/core/pcm_lib.c:1799
call_timer_fn+0x91/0x160 kernel/time/timer.c:1415
expire_timers kernel/time/timer.c:1460 [inline]
__run_timers+0x65e/0x830 kernel/time/timer.c:1757
run_timer_softirq+0x46/0x80 kernel/time/timer.c:1770
__do_softirq+0x256/0x6e0 kernel/softirq.c:298
asm_call_irq_on_stack+0xf/0x20
__run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
do_softirq_own_stack+0x9a/0xf0 arch/x86/kernel/irq_64.c:77
invoke_softirq kernel/softirq.c:393 [inline]
__irq_exit_rcu+0x21f/0x230 kernel/softirq.c:423
irq_exit_rcu+0x5/0x20 kernel/softirq.c:435
sysvec_apic_timer_interrupt+0xe0/0xf0 arch/x86/kernel/apic/apic.c:1091
asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581
native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60
arch_safe_halt arch/x86/include/asm/paravirt.h:150 [inline]
acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline]
acpi_idle_do_entry+0xde/0x2d0 drivers/acpi/processor_idle.c:517
acpi_idle_enter+0x2fa/0x440 drivers/acpi/processor_idle.c:648
cpuidle_enter_state+0x38a/0x980 drivers/cpuidle/cpuidle.c:237
cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:350
call_cpuidle kernel/sched/idle.c:132 [inline]
cpuidle_idle_call kernel/sched/idle.c:213 [inline]
do_idle+0x4a7/0x650 kernel/sched/idle.c:273
cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:369
start_kernel+0x4b0/0x57c init/main.c:1049
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243


stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.9.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1d6/0x29e lib/dump_stack.c:118
print_irq_inversion_bug+0xa5c/0xd70 kernel/locking/lockdep.c:3817
check_usage_forwards kernel/locking/lockdep.c:191 [inline]
mark_lock_irq kernel/locking/lockdep.c:3980 [inline]
mark_lock+0xe80/0x2050 kernel/locking/lockdep.c:4408
mark_usage kernel/locking/lockdep.c:4305 [inline]
__lock_acquire+0xa67/0x2bd0 kernel/locking/lockdep.c:4791
lock_acquire+0x160/0x710 kernel/locking/lockdep.c:5442
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xaa/0xd0 kernel/locking/spinlock.c:159
snd_pcm_period_elapsed+0x2c/0x210 sound/core/pcm_lib.c:1799
call_timer_fn+0x91/0x160 kernel/time/timer.c:1415
expire_timers kernel/time/timer.c:1460 [inline]
__run_timers+0x65e/0x830 kernel/time/timer.c:1757
run_timer_softirq+0x46/0x80 kernel/time/timer.c:1770
__do_softirq+0x256/0x6e0 kernel/softirq.c:298
asm_call_irq_on_stack+0xf/0x20
</IRQ>
__run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
do_softirq_own_stack+0x9a/0xf0 arch/x86/kernel/irq_64.c:77
invoke_softirq kernel/softirq.c:393 [inline]
__irq_exit_rcu+0x21f/0x230 kernel/softirq.c:423
irq_exit_rcu+0x5/0x20 kernel/softirq.c:435
sysvec_apic_timer_interrupt+0xe0/0xf0 arch/x86/kernel/apic/apic.c:1091
asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: 80 e1 07 80 c1 03 38 c1 7c bc 48 89 df e8 0a 4e 60 f9 eb b2 cc cc cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d f6 6a 4d 00 fb f4 <c3> 90 e9 07 00 00 00 0f 00 2d e6 6a 4d 00 f4 c3 cc cc 41 56 53 65
RSP: 0018:ffffffff89807d68 EFLAGS: 00000282
RAX: 1ffffffff131a5c7 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffffff817b4020 R09: fffffbfff1312d39
R10: fffffbfff1312d39 R11: 0000000000000000 R12: ffff8880a6732864
R13: ffff8880a3185804 R14: ffff8880a6732864 R15: dffffc0000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:150 [inline]
acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline]
acpi_idle_do_entry+0xde/0x2d0 drivers/acpi/processor_idle.c:517
acpi_idle_enter+0x2fa/0x440 drivers/acpi/processor_idle.c:648
cpuidle_enter_state+0x38a/0x980 drivers/cpuidle/cpuidle.c:237
cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:350
call_cpuidle kernel/sched/idle.c:132 [inline]
cpuidle_idle_call kernel/sched/idle.c:213 [inline]
do_idle+0x4a7/0x650 kernel/sched/idle.c:273
cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:369
start_kernel+0x4b0/0x57c init/main.c:1049
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243


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