======================================================== WARNING: possible irq lock inversion dependency detected 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted -------------------------------------------------------- udevd/4522 just changed the state of lock: ffff8880299e1110 (&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 udevd/4522: #0: ffff88807d3be8b8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xde/0x12c0 fs/seq_file.c:182 #1: ffff88802e551c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff888020873a00 (kn->active#5){.+.+}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 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_client_leave+0x37/0x1a0 sound/core/seq/seq_queue.c:543 seq_free_client1.part.0+0x10a/0x260 sound/core/seq/seq_clientmgr.c:285 seq_free_client1 sound/core/seq/seq_clientmgr.c:278 [inline] seq_free_client+0x74/0x170 sound/core/seq/seq_clientmgr.c:306 snd_seq_release+0x50/0xe0 sound/core/seq/seq_clientmgr.c:387 __fput+0x273/0xb80 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] __x64_sys_close+0x86/0x100 fs/open.c:1541 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd5/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 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_client_leave+0x37/0x1a0 sound/core/seq/seq_queue.c:543 seq_free_client1.part.0+0x10a/0x260 sound/core/seq/seq_clientmgr.c:285 seq_free_client1 sound/core/seq/seq_clientmgr.c:278 [inline] seq_free_client+0x74/0x170 sound/core/seq/seq_clientmgr.c:306 snd_seq_release+0x50/0xe0 sound/core/seq/seq_clientmgr.c:387 __fput+0x273/0xb80 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] __x64_sys_close+0x86/0x100 fs/open.c:1541 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd5/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 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_stop+0x197/0x1f0 sound/core/pcm_native.c:1520 snd_pcm_action_single+0x10d/0x150 sound/core/pcm_native.c:1289 snd_pcm_action+0x70/0x90 sound/core/pcm_native.c:1370 snd_pcm_stop sound/core/pcm_native.c:1543 [inline] snd_pcm_drop+0x165/0x2b0 sound/core/pcm_native.c:2208 snd_pcm_kernel_ioctl+0x22d/0x2d0 sound/core/pcm_native.c:3444 snd_pcm_oss_sync+0x227/0x7f0 sound/core/oss/pcm_oss.c:1734 snd_pcm_oss_release+0x291/0x320 sound/core/oss/pcm_oss.c:2575 __fput+0x273/0xb80 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] __x64_sys_close+0x86/0x100 fs/open.c:1541 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd5/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 } ... 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_stop+0x197/0x1f0 sound/core/pcm_native.c:1520 snd_pcm_action_single+0x10d/0x150 sound/core/pcm_native.c:1289 snd_pcm_action+0x70/0x90 sound/core/pcm_native.c:1370 snd_pcm_stop sound/core/pcm_native.c:1543 [inline] snd_pcm_drop+0x165/0x2b0 sound/core/pcm_native.c:2208 snd_pcm_kernel_ioctl+0x22d/0x2d0 sound/core/pcm_native.c:3444 snd_pcm_oss_sync+0x227/0x7f0 sound/core/oss/pcm_oss.c:1734 snd_pcm_oss_release+0x291/0x320 sound/core/oss/pcm_oss.c:2575 __fput+0x273/0xb80 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] __x64_sys_close+0x86/0x100 fs/open.c:1541 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd5/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 -> (&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 dummy_hrtimer_callback+0x9d/0x1c0 sound/drivers/dummy.c:385 __run_hrtimer kernel/time/hrtimer.c:1692 [inline] __hrtimer_run_queues+0x20f/0xc20 kernel/time/hrtimer.c:1756 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1773 __do_softirq+0x21b/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 stack_trace_consume_entry+0xf/0x170 kernel/stacktrace.c:83 arch_stack_walk+0xe4/0x170 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:240 [inline] __kasan_slab_free+0x11d/0x1a0 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2106 [inline] slab_free mm/slub.c:4280 [inline] kfree+0x129/0x370 mm/slub.c:4390 uevent_show+0x2c9/0x390 drivers/base/core.c:2669 dev_attr_show+0x56/0xe0 drivers/base/core.c:2364 sysfs_kf_seq_show+0x241/0x410 fs/sysfs/file.c:59 seq_read_iter+0x4fd/0x12c0 fs/seq_file.c:230 kernfs_fop_read_iter+0x417/0x580 fs/kernfs/file.c:279 call_read_iter include/linux/fs.h:2102 [inline] new_sync_read fs/read_write.c:395 [inline] vfs_read+0x6c3/0xb80 fs/read_write.c:476 ksys_read+0x12f/0x260 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd5/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 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+0x146c/0x3aa0 sound/core/oss/pcm_oss.c:965 snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1105 [inline] snd_pcm_oss_make_ready+0xe6/0x1b0 sound/core/oss/pcm_oss.c:1164 snd_pcm_oss_get_odelay sound/core/oss/pcm_oss.c:2166 [inline] snd_pcm_oss_ioctl+0x155a/0x37a0 sound/core/oss/pcm_oss.c:2732 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl fs/ioctl.c:890 [inline] __x64_sys_ioctl+0x196/0x220 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd5/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 } ... 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 dummy_hrtimer_callback+0x9d/0x1c0 sound/drivers/dummy.c:385 __run_hrtimer kernel/time/hrtimer.c:1692 [inline] __hrtimer_run_queues+0x20f/0xc20 kernel/time/hrtimer.c:1756 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1773 __do_softirq+0x21b/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 stack_trace_consume_entry+0xf/0x170 kernel/stacktrace.c:83 arch_stack_walk+0xe4/0x170 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:240 [inline] __kasan_slab_free+0x11d/0x1a0 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2106 [inline] slab_free mm/slub.c:4280 [inline] kfree+0x129/0x370 mm/slub.c:4390 uevent_show+0x2c9/0x390 drivers/base/core.c:2669 dev_attr_show+0x56/0xe0 drivers/base/core.c:2364 sysfs_kf_seq_show+0x241/0x410 fs/sysfs/file.c:59 seq_read_iter+0x4fd/0x12c0 fs/seq_file.c:230 kernfs_fop_read_iter+0x417/0x580 fs/kernfs/file.c:279 call_read_iter include/linux/fs.h:2102 [inline] new_sync_read fs/read_write.c:395 [inline] vfs_read+0x6c3/0xb80 fs/read_write.c:476 ksys_read+0x12f/0x260 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd5/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 stack backtrace: CPU: 1 PID: 4522 Comm: udevd Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 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 dummy_hrtimer_callback+0x9d/0x1c0 sound/drivers/dummy.c:385 __run_hrtimer kernel/time/hrtimer.c:1692 [inline] __hrtimer_run_queues+0x20f/0xc20 kernel/time/hrtimer.c:1756 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1773 __do_softirq+0x21b/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:stack_trace_consume_entry+0xf/0x170 kernel/stacktrace.c:83 Code: 6f 00 e9 db fc ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 55 <53> 48 89 fb 48 83 c7 10 48 89 fa 48 83 ec 08 48 c1 ea 03 0f b6 04 RSP: 0018:ffffc900031df748 EFLAGS: 00000293 RAX: dffffc0000000000 RBX: ffffffff8590f746 RCX: ffffffff8133f50e RDX: ffff888050730000 RSI: ffffffff8590f746 RDI: ffffc900031df820 RBP: ffffc900031df7f0 R08: 0000000000000007 R09: 0000000000000000 R10: ffffffff8590f746 R11: 0000000000000003 R12: ffffc900031df760 R13: ffffffff817a17d0 R14: ffffc900031df820 R15: ffff888050730000 arch_stack_walk+0xe4/0x170 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object mm/kasan/common.c:240 [inline] __kasan_slab_free+0x11d/0x1a0 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2106 [inline] slab_free mm/slub.c:4280 [inline] kfree+0x129/0x370 mm/slub.c:4390 uevent_show+0x2c9/0x390 drivers/base/core.c:2669 dev_attr_show+0x56/0xe0 drivers/base/core.c:2364 sysfs_kf_seq_show+0x241/0x410 fs/sysfs/file.c:59 seq_read_iter+0x4fd/0x12c0 fs/seq_file.c:230 kernfs_fop_read_iter+0x417/0x580 fs/kernfs/file.c:279 call_read_iter include/linux/fs.h:2102 [inline] new_sync_read fs/read_write.c:395 [inline] vfs_read+0x6c3/0xb80 fs/read_write.c:476 ksys_read+0x12f/0x260 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd5/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7f5434516b6a Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffc7f359ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000563acebd2520 RCX: 00007f5434516b6a RDX: 0000000000001000 RSI: 0000563acebdfc90 RDI: 000000000000000c RBP: 0000563acebd2520 R08: 000000000000000c R09: 0000000000000000 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007ffc7f35a1c8 R15: 000000000000000a TCP: request_sock_TCP: Possible SYN flooding on port [::]:2. Sending cookies. TCP: request_sock_TCP: Possible SYN flooding on port [::]:2. Sending cookies. ---------------- Code disassembly (best guess), 2 bytes skipped: 0: e9 db fc ff ff jmp 0xfffffce0 5: 0f 1f 40 00 nopl 0x0(%rax) 9: 90 nop a: 90 nop b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: f3 0f 1e fa endbr64 1d: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 24: fc ff df 27: 55 push %rbp * 28: 53 push %rbx <-- trapping instruction 29: 48 89 fb mov %rdi,%rbx 2c: 48 83 c7 10 add $0x10,%rdi 30: 48 89 fa mov %rdi,%rdx 33: 48 83 ec 08 sub $0x8,%rsp 37: 48 c1 ea 03 shr $0x3,%rdx 3b: 0f .byte 0xf 3c: b6 04 mov $0x4,%dh