======================================================== WARNING: possible irq lock inversion dependency detected 5.9.0-syzkaller #0 Not tainted -------------------------------------------------------- syz-executor.0/8551 just changed the state of lock: ffff888214d45108 (&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); lock(&group->lock); *** DEADLOCK *** 1 lock held by syz-executor.0/8551: #0: ffffc90000da8db0 ((&dpcm->timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:45 [inline] #0: ffffc90000da8db0 ((&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: [] 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 sound/core/oss/pcm_oss.c:1353 [inline] snd_pcm_oss_sync1+0x299/0x770 sound/core/oss/pcm_oss.c:1594 snd_pcm_oss_sync+0x5b9/0x900 sound/core/oss/pcm_oss.c:1659 snd_pcm_oss_ioctl+0x8a3/0x4660 sound/core/oss/pcm_oss.c:2590 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739 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 lockdep_enabled+0x30/0xa0 kernel/locking/lockdep.c:87 lock_is_held_type+0x15/0x100 kernel/locking/lockdep.c:5474 lock_is_held include/linux/lockdep.h:271 [inline] rcu_read_lock_sched_held+0x2f/0xa0 kernel/rcu/update.c:136 trace_lock_acquire+0x131/0x190 include/trace/events/lock.h:13 lock_acquire+0x39/0x710 kernel/locking/lockdep.c:5413 __fs_reclaim_acquire+0x20/0x30 mm/page_alloc.c:4234 slab_pre_alloc_hook+0x20/0xe0 mm/slab.h:495 slab_alloc mm/slab.c:3302 [inline] kmem_cache_alloc_trace+0x51/0x2e0 mm/slab.c:3552 kmalloc include/linux/slab.h:554 [inline] kmalloc_array include/linux/slab.h:593 [inline] kcalloc include/linux/slab.h:605 [inline] func_states_equal kernel/bpf/verifier.c:8365 [inline] states_equal+0x1f5/0xab0 kernel/bpf/verifier.c:8410 is_state_visited kernel/bpf/verifier.c:8615 [inline] do_check+0x177d/0x2aa80 kernel/bpf/verifier.c:8831 do_check_common+0x824/0x19f0 kernel/bpf/verifier.c:10663 do_check_main kernel/bpf/verifier.c:10729 [inline] bpf_check+0xfe40/0x11700 kernel/bpf/verifier.c:11182 bpf_prog_load kernel/bpf/syscall.c:2199 [inline] __do_sys_bpf+0xfe71/0x110b0 kernel/bpf/syscall.c:4178 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 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_change_params sound/core/oss/pcm_oss.c:1084 [inline] snd_pcm_oss_make_ready+0x115/0x2b0 sound/core/oss/pcm_oss.c:1143 snd_pcm_oss_sync+0x265/0x900 sound/core/oss/pcm_oss.c:1642 snd_pcm_oss_release+0x119/0x270 sound/core/oss/pcm_oss.c:2546 __fput+0x34f/0x7b0 fs/file_table.c:281 task_work_run+0x137/0x1c0 kernel/task_work.c:141 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:165 [inline] exit_to_user_mode_prepare+0x125/0x1f0 kernel/entry/common.c:192 syscall_exit_to_user_mode+0x82/0x1d0 kernel/entry/common.c:267 entry_SYSCALL_64_after_hwframe+0x44/0xa9 } ... key at: [] 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 lockdep_enabled+0x30/0xa0 kernel/locking/lockdep.c:87 lock_is_held_type+0x15/0x100 kernel/locking/lockdep.c:5474 lock_is_held include/linux/lockdep.h:271 [inline] rcu_read_lock_sched_held+0x2f/0xa0 kernel/rcu/update.c:136 trace_lock_acquire+0x131/0x190 include/trace/events/lock.h:13 lock_acquire+0x39/0x710 kernel/locking/lockdep.c:5413 __fs_reclaim_acquire+0x20/0x30 mm/page_alloc.c:4234 slab_pre_alloc_hook+0x20/0xe0 mm/slab.h:495 slab_alloc mm/slab.c:3302 [inline] kmem_cache_alloc_trace+0x51/0x2e0 mm/slab.c:3552 kmalloc include/linux/slab.h:554 [inline] kmalloc_array include/linux/slab.h:593 [inline] kcalloc include/linux/slab.h:605 [inline] func_states_equal kernel/bpf/verifier.c:8365 [inline] states_equal+0x1f5/0xab0 kernel/bpf/verifier.c:8410 is_state_visited kernel/bpf/verifier.c:8615 [inline] do_check+0x177d/0x2aa80 kernel/bpf/verifier.c:8831 do_check_common+0x824/0x19f0 kernel/bpf/verifier.c:10663 do_check_main kernel/bpf/verifier.c:10729 [inline] bpf_check+0xfe40/0x11700 kernel/bpf/verifier.c:11182 bpf_prog_load kernel/bpf/syscall.c:2199 [inline] __do_sys_bpf+0xfe71/0x110b0 kernel/bpf/syscall.c:4178 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 stack backtrace: CPU: 1 PID: 8551 Comm: syz-executor.0 Not tainted 5.9.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __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 __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:lockdep_enabled+0x30/0xa0 kernel/locking/lockdep.c:87 Code: c4 ff d1 89 48 c1 e8 03 49 be 00 00 00 00 00 fc ff df 42 8a 04 30 84 c0 75 41 83 3d dd d8 77 08 00 74 0b 65 8b 05 10 e7 a7 7e <85> c0 74 04 31 c0 eb 25 65 48 8b 1c 25 00 fe 01 00 48 81 c3 ec 08 RSP: 0018:ffffc90005fc7388 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000080000001 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff898fffe0 RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff13a398e R10: fffffbfff13a398e R11: 0000000000000000 R12: ffffffff898fffe0 R13: 0000000000000000 R14: dffffc0000000000 R15: 00000000ffffffff lock_is_held_type+0x15/0x100 kernel/locking/lockdep.c:5474 lock_is_held include/linux/lockdep.h:271 [inline] rcu_read_lock_sched_held+0x2f/0xa0 kernel/rcu/update.c:136 trace_lock_acquire+0x131/0x190 include/trace/events/lock.h:13 lock_acquire+0x39/0x710 kernel/locking/lockdep.c:5413 __fs_reclaim_acquire+0x20/0x30 mm/page_alloc.c:4234 slab_pre_alloc_hook+0x20/0xe0 mm/slab.h:495 slab_alloc mm/slab.c:3302 [inline] kmem_cache_alloc_trace+0x51/0x2e0 mm/slab.c:3552 kmalloc include/linux/slab.h:554 [inline] kmalloc_array include/linux/slab.h:593 [inline] kcalloc include/linux/slab.h:605 [inline] func_states_equal kernel/bpf/verifier.c:8365 [inline] states_equal+0x1f5/0xab0 kernel/bpf/verifier.c:8410 is_state_visited kernel/bpf/verifier.c:8615 [inline] do_check+0x177d/0x2aa80 kernel/bpf/verifier.c:8831 do_check_common+0x824/0x19f0 kernel/bpf/verifier.c:10663 do_check_main kernel/bpf/verifier.c:10729 [inline] bpf_check+0xfe40/0x11700 kernel/bpf/verifier.c:11182 bpf_prog_load kernel/bpf/syscall.c:2199 [inline] __do_sys_bpf+0xfe71/0x110b0 kernel/bpf/syscall.c:4178 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45de59 Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f10ce87ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 0000000000001cc0 RCX: 000000000045de59 RDX: 0000000000000048 RSI: 00000000200054c0 RDI: 0000000000000005 RBP: 000000000118c008 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bfd4 R13: 00007ffd2950718f R14: 00007f10ce87b9c0 R15: 000000000118bfd4