======================================================== WARNING: possible irq lock inversion dependency detected 6.8.0-syzkaller-09791-ge5eb28f6d1af #0 Not tainted -------------------------------------------------------- kswapd1/111 just changed the state of lock: ffff88801b8b4910 (&group->lock#2){..-.}-{2:2}, at: _snd_pcm_stream_lock_irqsave+0xa0/0xd0 sound/core/pcm_native.c:170 but this lock took another, SOFTIRQ-unsafe lock in the past: (&timer->lock){+.+.}-{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(&timer->lock); local_irq_disable(); lock(&group->lock#2); lock(&timer->lock); lock(&group->lock#2 ); *** DEADLOCK *** 3 locks held by kswapd1/111: #0: ffffffff8d937340 (fs_reclaim){+.+.}-{0:0} , at: balance_pgdat+0x166/0x1a10 mm/vmscan.c:6782 #1: ffffffff8d7b3fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] (rcu_read_lock){....}-{1:2}, at: folio_evictable mm/internal.h:255 [inline] (rcu_read_lock){....}-{1:2}, at: evict_folios+0x9ed/0x1b90 mm/vmscan.c:4544 #2: ffffc90000007cb0 ((&dpcm->timer)){+.-.}-{0:0}, at: call_timer_fn+0x11a/0x5b0 kernel/time/timer.c:1789 the shortest dependencies between 2nd lock and 1st lock: -> (&timer->lock){+.+.}-{2:2} { HARDIRQ-ON-W at: lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] class_spinlock_constructor include/linux/spinlock.h:561 [inline] snd_timer_close_locked+0x65/0xbd0 sound/core/timer.c:412 snd_timer_close+0x8b/0xf0 sound/core/timer.c:464 snd_seq_timer_close+0xa4/0x100 sound/core/seq/seq_timer.c:302 queue_delete+0x49/0xa0 sound/core/seq/seq_queue.c:126 snd_seq_queue_delete+0x45/0x60 sound/core/seq/seq_queue.c:188 snd_seq_kernel_client_ctl+0x107/0x1c0 sound/core/seq/seq_clientmgr.c:2526 delete_seq_queue.isra.0+0xca/0x150 sound/core/seq/oss/seq_oss_init.c:371 odev_release+0x52/0x80 sound/core/seq/oss/seq_oss.c:144 __fput+0x270/0xb80 fs/file_table.c:422 __fput_sync+0x47/0x50 fs/file_table.c:507 __do_sys_close fs/open.c:1556 [inline] __se_sys_close fs/open.c:1541 [inline] __ia32_sys_close+0x86/0x100 fs/open.c:1541 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x7a/0x120 arch/x86/entry/common.c:321 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x7a/0x84 SOFTIRQ-ON-W at: lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] class_spinlock_constructor include/linux/spinlock.h:561 [inline] snd_timer_close_locked+0x65/0xbd0 sound/core/timer.c:412 snd_timer_close+0x8b/0xf0 sound/core/timer.c:464 snd_seq_timer_close+0xa4/0x100 sound/core/seq/seq_timer.c:302 queue_delete+0x49/0xa0 sound/core/seq/seq_queue.c:126 snd_seq_queue_delete+0x45/0x60 sound/core/seq/seq_queue.c:188 snd_seq_kernel_client_ctl+0x107/0x1c0 sound/core/seq/seq_clientmgr.c:2526 delete_seq_queue.isra.0+0xca/0x150 sound/core/seq/oss/seq_oss_init.c:371 odev_release+0x52/0x80 sound/core/seq/oss/seq_oss.c:144 __fput+0x270/0xb80 fs/file_table.c:422 __fput_sync+0x47/0x50 fs/file_table.c:507 __do_sys_close fs/open.c:1556 [inline] __se_sys_close fs/open.c:1541 [inline] __ia32_sys_close+0x86/0x100 fs/open.c:1541 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x7a/0x120 arch/x86/entry/common.c:321 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x7a/0x84 INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 class_spinlock_irqsave_constructor include/linux/spinlock.h:574 [inline] snd_timer_notify+0x111/0x3e0 sound/core/timer.c:1040 snd_pcm_timer_notify sound/core/pcm_native.c:622 [inline] snd_pcm_post_start+0x272/0x350 sound/core/pcm_native.c:1459 snd_pcm_action_single+0x10a/0x150 sound/core/pcm_native.c:1289 snd_pcm_action+0x70/0x90 sound/core/pcm_native.c:1370 snd_pcm_action_lock_irq+0xa1/0x1a0 sound/core/pcm_native.c:1383 snd_pcm_start_lock_irq sound/core/pcm_native.c:1485 [inline] snd_pcm_kernel_ioctl+0x10f/0x2d0 sound/core/pcm_native.c:3440 snd_pcm_oss_post sound/core/oss/pcm_oss.c:1594 [inline] snd_pcm_oss_ioctl+0x1b06/0x37a0 sound/core/oss/pcm_oss.c:2673 __do_compat_sys_ioctl+0x2c3/0x330 fs/ioctl.c:1004 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x7a/0x120 arch/x86/entry/common.c:321 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x7a/0x84 } ... key at: [] __key.6+0x0/0x40 ... acquired at: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 class_spinlock_irqsave_constructor include/linux/spinlock.h:574 [inline] snd_timer_notify+0x111/0x3e0 sound/core/timer.c:1040 snd_pcm_timer_notify sound/core/pcm_native.c:622 [inline] snd_pcm_post_start+0x272/0x350 sound/core/pcm_native.c:1459 snd_pcm_action_single+0x10a/0x150 sound/core/pcm_native.c:1289 snd_pcm_action+0x70/0x90 sound/core/pcm_native.c:1370 snd_pcm_action_lock_irq+0xa1/0x1a0 sound/core/pcm_native.c:1383 snd_pcm_start_lock_irq sound/core/pcm_native.c:1485 [inline] snd_pcm_kernel_ioctl+0x10f/0x2d0 sound/core/pcm_native.c:3440 snd_pcm_oss_post sound/core/oss/pcm_oss.c:1594 [inline] snd_pcm_oss_ioctl+0x1b06/0x37a0 sound/core/oss/pcm_oss.c:2673 __do_compat_sys_ioctl+0x2c3/0x330 fs/ioctl.c:1004 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x7a/0x120 arch/x86/entry/common.c:321 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x7a/0x84 -> (&group->lock#2){..-.}-{2:2} { IN-SOFTIRQ-W at: lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 _snd_pcm_stream_lock_irqsave+0xa0/0xd0 sound/core/pcm_native.c:170 class_pcm_stream_lock_irqsave_constructor include/sound/pcm.h:669 [inline] snd_pcm_period_elapsed+0x20/0x50 sound/core/pcm_lib.c:1904 loopback_jiffies_timer_function+0x1c8/0x240 sound/drivers/aloop.c:713 call_timer_fn+0x1a0/0x5b0 kernel/time/timer.c:1792 expire_timers kernel/time/timer.c:1843 [inline] __run_timers+0x74b/0xab0 kernel/time/timer.c:2408 __run_timer_base kernel/time/timer.c:2419 [inline] __run_timer_base kernel/time/timer.c:2412 [inline] run_timer_base+0x111/0x190 kernel/time/timer.c:2428 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2438 __do_softirq+0x218/0x8de kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:633 [inline] irq_exit_rcu+0xb9/0x120 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 check_kcov_mode kernel/kcov.c:175 [inline] write_comp_data+0x34/0x90 kernel/kcov.c:236 const_folio_flags+0x64/0x1f0 include/linux/page-flags.h:315 folio_test_mlocked include/linux/page-flags.h:583 [inline] folio_evictable mm/internal.h:257 [inline] evict_folios+0xa7b/0x1b90 mm/vmscan.c:4544 try_to_shrink_lruvec+0x618/0x9b0 mm/vmscan.c:4733 shrink_one+0x3f8/0x7c0 mm/vmscan.c:4772 shrink_many mm/vmscan.c:4835 [inline] lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4935 shrink_node mm/vmscan.c:5894 [inline] kswapd_shrink_node mm/vmscan.c:6704 [inline] balance_pgdat+0x10d1/0x1a10 mm/vmscan.c:6895 kswapd+0x5ea/0xb90 mm/vmscan.c:7164 kthread+0x2c1/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170 spin_lock_irq include/linux/spinlock.h:376 [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] class_pcm_stream_lock_irq_constructor include/sound/pcm.h:666 [inline] snd_pcm_hw_params+0x151/0x1a30 sound/core/pcm_native.c:740 snd_pcm_kernel_ioctl+0x147/0x2d0 sound/core/pcm_native.c:3434 snd_pcm_oss_change_params_locked+0x1476/0x3aa0 sound/core/oss/pcm_oss.c:965 snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1105 [inline] snd_pcm_oss_get_active_substream+0x168/0x1d0 sound/core/oss/pcm_oss.c:1122 snd_pcm_oss_get_formats+0x7e/0x330 sound/core/oss/pcm_oss.c:1843 snd_pcm_oss_set_format sound/core/oss/pcm_oss.c:1883 [inline] snd_pcm_oss_ioctl+0x2ef7/0x37a0 sound/core/oss/pcm_oss.c:2648 __do_compat_sys_ioctl+0x2c3/0x330 fs/ioctl.c:1004 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x7a/0x120 arch/x86/entry/common.c:321 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:346 entry_SYSENTER_compat_after_hwframe+0x7a/0x84 } ... key at: [] __key.5+0x0/0x40 ... acquired at: mark_usage kernel/locking/lockdep.c:4567 [inline] __lock_acquire+0x13d4/0x3b30 kernel/locking/lockdep.c:5091 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 _snd_pcm_stream_lock_irqsave+0xa0/0xd0 sound/core/pcm_native.c:170 class_pcm_stream_lock_irqsave_constructor include/sound/pcm.h:669 [inline] snd_pcm_period_elapsed+0x20/0x50 sound/core/pcm_lib.c:1904 loopback_jiffies_timer_function+0x1c8/0x240 sound/drivers/aloop.c:713 call_timer_fn+0x1a0/0x5b0 kernel/time/timer.c:1792 expire_timers kernel/time/timer.c:1843 [inline] __run_timers+0x74b/0xab0 kernel/time/timer.c:2408 __run_timer_base kernel/time/timer.c:2419 [inline] __run_timer_base kernel/time/timer.c:2412 [inline] run_timer_base+0x111/0x190 kernel/time/timer.c:2428 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2438 __do_softirq+0x218/0x8de kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:633 [inline] irq_exit_rcu+0xb9/0x120 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 check_kcov_mode kernel/kcov.c:175 [inline] write_comp_data+0x34/0x90 kernel/kcov.c:236 const_folio_flags+0x64/0x1f0 include/linux/page-flags.h:315 folio_test_mlocked include/linux/page-flags.h:583 [inline] folio_evictable mm/internal.h:257 [inline] evict_folios+0xa7b/0x1b90 mm/vmscan.c:4544 try_to_shrink_lruvec+0x618/0x9b0 mm/vmscan.c:4733 shrink_one+0x3f8/0x7c0 mm/vmscan.c:4772 shrink_many mm/vmscan.c:4835 [inline] lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4935 shrink_node mm/vmscan.c:5894 [inline] kswapd_shrink_node mm/vmscan.c:6704 [inline] balance_pgdat+0x10d1/0x1a10 mm/vmscan.c:6895 kswapd+0x5ea/0xb90 mm/vmscan.c:7164 kthread+0x2c1/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 stack backtrace: CPU: 0 PID: 111 Comm: kswapd1 Not tainted 6.8.0-syzkaller-09791-ge5eb28f6d1af #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 print_irq_inversion_bug.part.0+0x3e9/0x5a0 kernel/locking/lockdep.c:4080 print_irq_inversion_bug kernel/locking/lockdep.c:4033 [inline] check_usage_forwards kernel/locking/lockdep.c:4111 [inline] mark_lock_irq kernel/locking/lockdep.c:4243 [inline] mark_lock+0x574/0xc60 kernel/locking/lockdep.c:4678 mark_usage kernel/locking/lockdep.c:4567 [inline] __lock_acquire+0x13d4/0x3b30 kernel/locking/lockdep.c:5091 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 _snd_pcm_stream_lock_irqsave+0xa0/0xd0 sound/core/pcm_native.c:170 class_pcm_stream_lock_irqsave_constructor include/sound/pcm.h:669 [inline] snd_pcm_period_elapsed+0x20/0x50 sound/core/pcm_lib.c:1904 loopback_jiffies_timer_function+0x1c8/0x240 sound/drivers/aloop.c:713 call_timer_fn+0x1a0/0x5b0 kernel/time/timer.c:1792 expire_timers kernel/time/timer.c:1843 [inline] __run_timers+0x74b/0xab0 kernel/time/timer.c:2408 __run_timer_base kernel/time/timer.c:2419 [inline] __run_timer_base kernel/time/timer.c:2412 [inline] run_timer_base+0x111/0x190 kernel/time/timer.c:2428 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2438 __do_softirq+0x218/0x8de kernel/softirq.c:554 invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:633 [inline] irq_exit_rcu+0xb9/0x120 kernel/softirq.c:645 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:write_comp_data+0x34/0x90 kernel/kcov.c:236 Code: 48 8b 15 5f 44 76 7e 65 8b 05 60 44 76 7e a9 00 01 ff 00 74 0f f6 c4 01 74 59 8b 82 14 16 00 00 85 c0 74 4f 8b 82 f0 15 00 00 <83> f8 03 75 44 48 8b 82 f8 15 00 00 8b 92 f4 15 00 00 48 8b 38 48 RSP: 0018:ffffc90001fcf5f0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81c54f74 RDX: ffff88801ae28000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: ffffea0001991a80 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: ffffea0001991a88 R14: ffffea0001991ac0 R15: dffffc0000000000 const_folio_flags+0x64/0x1f0 include/linux/page-flags.h:315 folio_test_mlocked include/linux/page-flags.h:583 [inline] folio_evictable mm/internal.h:257 [inline] evict_folios+0xa7b/0x1b90 mm/vmscan.c:4544 try_to_shrink_lruvec+0x618/0x9b0 mm/vmscan.c:4733 shrink_one+0x3f8/0x7c0 mm/vmscan.c:4772 shrink_many mm/vmscan.c:4835 [inline] lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4935 shrink_node mm/vmscan.c:5894 [inline] kswapd_shrink_node mm/vmscan.c:6704 [inline] balance_pgdat+0x10d1/0x1a10 mm/vmscan.c:6895 kswapd+0x5ea/0xb90 mm/vmscan.c:7164 kthread+0x2c1/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 ---------------- Code disassembly (best guess): 0: 48 8b 15 5f 44 76 7e mov 0x7e76445f(%rip),%rdx # 0x7e764466 7: 65 8b 05 60 44 76 7e mov %gs:0x7e764460(%rip),%eax # 0x7e76446e e: a9 00 01 ff 00 test $0xff0100,%eax 13: 74 0f je 0x24 15: f6 c4 01 test $0x1,%ah 18: 74 59 je 0x73 1a: 8b 82 14 16 00 00 mov 0x1614(%rdx),%eax 20: 85 c0 test %eax,%eax 22: 74 4f je 0x73 24: 8b 82 f0 15 00 00 mov 0x15f0(%rdx),%eax * 2a: 83 f8 03 cmp $0x3,%eax <-- trapping instruction 2d: 75 44 jne 0x73 2f: 48 8b 82 f8 15 00 00 mov 0x15f8(%rdx),%rax 36: 8b 92 f4 15 00 00 mov 0x15f4(%rdx),%edx 3c: 48 8b 38 mov (%rax),%rdi 3f: 48 rex.W