======================================================== WARNING: possible irq lock inversion dependency detected 5.9.0-syzkaller #0 Not tainted -------------------------------------------------------- syz-executor.0/8846 just changed the state of lock: ffff888214d60908 (&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.0/8846: #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+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 __orc_find arch/x86/kernel/unwind_orc.c:49 [inline] orc_find arch/x86/kernel/unwind_orc.c:172 [inline] unwind_next_frame+0x293/0x1e90 arch/x86/kernel/unwind_orc.c:449 arch_stack_walk+0xb2/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xad/0x150 kernel/stacktrace.c:121 kasan_save_stack mm/kasan/common.c:48 [inline] kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc+0x100/0x130 mm/kasan/common.c:461 slab_post_alloc_hook+0x3e/0x290 mm/slab.h:518 slab_alloc mm/slab.c:3316 [inline] kmem_cache_alloc+0x1c1/0x2d0 mm/slab.c:3486 kmem_cache_zalloc include/linux/slab.h:656 [inline] __delayacct_tsk_init+0x1c/0x90 kernel/delayacct.c:36 delayacct_tsk_init include/linux/delayacct.h:102 [inline] copy_process+0x9e3/0x5280 kernel/fork.c:1965 _do_fork+0x1ab/0x6e0 kernel/fork.c:2435 __do_sys_clone kernel/fork.c:2552 [inline] __se_sys_clone kernel/fork.c:2536 [inline] __x64_sys_clone+0x1e9/0x230 kernel/fork.c:2536 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_status64+0xcc/0x10b0 sound/core/pcm_native.c:926 snd_pcm_status_user32+0xe2/0x880 sound/core/pcm_native.c:1039 snd_pcm_common_ioctl+0x11cf/0x87e0 sound/core/pcm_native.c:3218 snd_pcm_ioctl+0x86/0xa0 sound/core/pcm_native.c:3295 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 } ... 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 __orc_find arch/x86/kernel/unwind_orc.c:49 [inline] orc_find arch/x86/kernel/unwind_orc.c:172 [inline] unwind_next_frame+0x293/0x1e90 arch/x86/kernel/unwind_orc.c:449 arch_stack_walk+0xb2/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xad/0x150 kernel/stacktrace.c:121 kasan_save_stack mm/kasan/common.c:48 [inline] kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc+0x100/0x130 mm/kasan/common.c:461 slab_post_alloc_hook+0x3e/0x290 mm/slab.h:518 slab_alloc mm/slab.c:3316 [inline] kmem_cache_alloc+0x1c1/0x2d0 mm/slab.c:3486 kmem_cache_zalloc include/linux/slab.h:656 [inline] __delayacct_tsk_init+0x1c/0x90 kernel/delayacct.c:36 delayacct_tsk_init include/linux/delayacct.h:102 [inline] copy_process+0x9e3/0x5280 kernel/fork.c:1965 _do_fork+0x1ab/0x6e0 kernel/fork.c:2435 __do_sys_clone kernel/fork.c:2552 [inline] __se_sys_clone kernel/fork.c:2536 [inline] __x64_sys_clone+0x1e9/0x230 kernel/fork.c:2536 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 stack backtrace: CPU: 1 PID: 8846 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:__orc_find arch/x86/kernel/unwind_orc.c:49 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:172 [inline] RIP: 0010:unwind_next_frame+0x293/0x1e90 arch/x86/kernel/unwind_orc.c:449 Code: f7 4c 39 f5 0f 82 b5 01 00 00 4d 89 f7 4d 89 f5 eb 15 0f 1f 44 00 00 4c 8d 6b 04 49 89 df 49 39 ed 0f 87 98 01 00 00 48 89 e8 <4c> 29 e8 48 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe 49 RSP: 0018:ffffc90004b5f7a0 EFLAGS: 00000246 RAX: ffffffff8a40bdac RBX: ffffffff8a40bda8 RCX: dffffc0000000000 RDX: ffffffff8ada1722 RSI: ffffffff88528c01 RDI: ffffffff8134377d RBP: ffffffff8a40bdac R08: 0000000000000048 R09: ffffc90004b5f918 R10: fffff5200096bf19 R11: 0000000000000000 R12: ffffffff88528c60 R13: ffffffff8a40bdac R14: ffffffff8a40bd90 R15: ffffffff8a40bda8 arch_stack_walk+0xb2/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xad/0x150 kernel/stacktrace.c:121 kasan_save_stack mm/kasan/common.c:48 [inline] kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc+0x100/0x130 mm/kasan/common.c:461 slab_post_alloc_hook+0x3e/0x290 mm/slab.h:518 slab_alloc mm/slab.c:3316 [inline] kmem_cache_alloc+0x1c1/0x2d0 mm/slab.c:3486 kmem_cache_zalloc include/linux/slab.h:656 [inline] __delayacct_tsk_init+0x1c/0x90 kernel/delayacct.c:36 delayacct_tsk_init include/linux/delayacct.h:102 [inline] copy_process+0x9e3/0x5280 kernel/fork.c:1965 _do_fork+0x1ab/0x6e0 kernel/fork.c:2435 __do_sys_clone kernel/fork.c:2552 [inline] __se_sys_clone kernel/fork.c:2536 [inline] __x64_sys_clone+0x1e9/0x230 kernel/fork.c:2536 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x460829 Code: ff 48 85 f6 0f 84 37 8a fb ff 48 83 ee 10 48 89 4e 08 48 89 3e 48 89 d7 4c 89 c2 4d 89 c8 4c 8b 54 24 08 b8 38 00 00 00 0f 05 <48> 85 c0 0f 8c 0e 8a fb ff 74 01 c3 31 ed 48 f7 c7 00 00 01 00 75 RSP: 002b:00007ffed047b158 EFLAGS: 00000202 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f0e488ee700 RCX: 0000000000460829 RDX: 00007f0e488ee9d0 RSI: 00007f0e488eddb0 RDI: 00000000003d0f00 RBP: 00007ffed047b370 R08: 00007f0e488ee700 R09: 00007f0e488ee700 R10: 00007f0e488ee9d0 R11: 0000000000000202 R12: 0000000000000000 R13: 00007ffed047b20f R14: 00007f0e488ee9c0 R15: 000000000118c07c