======================================================== WARNING: possible irq lock inversion dependency detected 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted -------------------------------------------------------- kworker/u8:1/11 just changed the state of lock: ffff888029cbf110 (&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 *** 4 locks held by kworker/u8:1/11: #0: ffff88802ac74148 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x1296/0x1a60 kernel/workqueue.c:3229 #1: ffffc90000107d80 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x906/0x1a60 kernel/workqueue.c:3230 #2: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #2: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #2: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] #2: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: batadv_nc_worker+0x168/0x10f0 net/batman-adv/network-coding.c:719 #3: ffffc90000a08cb0 ((&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_timer_user_release+0x91/0x260 sound/core/timer.c:1468 __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] __x64_sys_close+0x86/0x100 fs/open.c:1541 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 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_timer_user_release+0x91/0x260 sound/core/timer.c:1468 __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] __x64_sys_close+0x86/0x100 fs/open.c:1541 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 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_stop1+0x60/0x890 sound/core/timer.c:602 snd_timer_stop sound/core/timer.c:679 [inline] snd_timer_user_params.isra.0+0x328/0x920 sound/core/timer.c:1811 __snd_timer_user_ioctl.isra.0+0x1096/0x2620 sound/core/timer.c:2031 snd_timer_user_ioctl+0x7b/0xc0 sound/core/timer.c:2058 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+0x193/0x220 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 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_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_lib_xfer+0x175b/0x1ea0 sound/core/pcm_lib.c:2301 snd_pcm_oss_read3+0x18e/0x2d0 sound/core/oss/pcm_oss.c:1281 io_capture_transfer+0x273/0x300 sound/core/oss/io.c:73 snd_pcm_plug_read_transfer+0x1b3/0x300 sound/core/oss/pcm_plugin.c:663 snd_pcm_oss_read2+0x1dc/0x3d0 sound/core/oss/pcm_oss.c:1482 snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1539 [inline] snd_pcm_oss_read+0x5af/0x760 sound/core/oss/pcm_oss.c:2773 vfs_read+0x1d4/0xb80 fs/read_write.c:474 ksys_read+0x12f/0x260 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 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 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 preempt_schedule_irq+0x4c/0x90 kernel/sched/core.c:7058 irqentry_exit+0x36/0x90 kernel/entry/common.c:348 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 lock_acquire+0x1f2/0x540 kernel/locking/lockdep.c:5722 rcu_lock_acquire include/linux/rcupdate.h:298 [inline] rcu_read_lock include/linux/rcupdate.h:750 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x16e/0x10f0 net/batman-adv/network-coding.c:719 process_one_work+0x9a9/0x1a60 kernel/workqueue.c:3254 process_scheduled_works kernel/workqueue.c:3335 [inline] worker_thread+0x6c8/0xf70 kernel/workqueue.c:3416 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+0x146c/0x3aa0 sound/core/oss/pcm_oss.c:965 snd_pcm_oss_make_ready_locked+0xb7/0x130 sound/core/oss/pcm_oss.c:1187 snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1515 [inline] snd_pcm_oss_read+0x3a2/0x760 sound/core/oss/pcm_oss.c:2773 vfs_read+0x1d4/0xb80 fs/read_write.c:474 ksys_read+0x12f/0x260 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 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 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 preempt_schedule_irq+0x4c/0x90 kernel/sched/core.c:7058 irqentry_exit+0x36/0x90 kernel/entry/common.c:348 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 lock_acquire+0x1f2/0x540 kernel/locking/lockdep.c:5722 rcu_lock_acquire include/linux/rcupdate.h:298 [inline] rcu_read_lock include/linux/rcupdate.h:750 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x16e/0x10f0 net/batman-adv/network-coding.c:719 process_one_work+0x9a9/0x1a60 kernel/workqueue.c:3254 process_scheduled_works kernel/workqueue.c:3335 [inline] worker_thread+0x6c8/0xf70 kernel/workqueue.c:3416 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: 1 PID: 11 Comm: kworker/u8:1 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: bat_events batadv_nc_worker 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:preempt_schedule_irq+0x4c/0x90 kernel/sched/core.c:7058 Code: df 55 65 48 8b 2d f4 01 2f 75 53 48 89 eb 48 c1 eb 03 48 01 c3 bf 01 00 00 00 e8 1f 8c 88 f6 e8 5a 36 bf f6 fb bf 01 00 00 00 df 92 ff ff 9c 58 fa f6 c4 02 75 1e bf 01 00 00 00 e8 6d 39 88 RSP: 0018:ffffc900001079d8 EFLAGS: 00000206 RAX: 00000000002ded59 RBX: ffffed1002ddc780 RCX: 1ffffffff27bfab9 RDX: 0000000000000000 RSI: ffffffff8b0cb740 RDI: 0000000000000001 RBP: ffff888016ee3c00 R08: 0000000000000001 R09: fffffbfff27b4e4b R10: ffffffff93da725f R11: 0000000000000003 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 irqentry_exit+0x36/0x90 kernel/entry/common.c:348 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x1f2/0x540 kernel/locking/lockdep.c:5722 Code: c1 05 ea 37 97 7e 83 f8 01 0f 85 c8 02 00 00 9c 58 f6 c4 02 0f 85 b3 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90000107aa8 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff92000020f57 RCX: 00000000d5afbc4a RDX: 0000000000000001 RSI: ffffffff8b0cba40 RDI: ffffffff8b6e88a0 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff27b4e30 R10: ffffffff93da7187 R11: 0000000000000002 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8d7b08e0 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:298 [inline] rcu_read_lock include/linux/rcupdate.h:750 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x16e/0x10f0 net/batman-adv/network-coding.c:719 process_one_work+0x9a9/0x1a60 kernel/workqueue.c:3254 process_scheduled_works kernel/workqueue.c:3335 [inline] worker_thread+0x6c8/0xf70 kernel/workqueue.c:3416 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 vkms_vblank_simulate: vblank timer overrun vkms_vblank_simulate: vblank timer overrun ---------------- Code disassembly (best guess): 0: df 55 65 fists 0x65(%rbp) 3: 48 8b 2d f4 01 2f 75 mov 0x752f01f4(%rip),%rbp # 0x752f01fe a: 53 push %rbx b: 48 89 eb mov %rbp,%rbx e: 48 c1 eb 03 shr $0x3,%rbx 12: 48 01 c3 add %rax,%rbx 15: bf 01 00 00 00 mov $0x1,%edi 1a: e8 1f 8c 88 f6 call 0xf6888c3e 1f: e8 5a 36 bf f6 call 0xf6bf367e 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 df 92 ff ff call 0xffff930e <-- trapping instruction 2f: 9c pushf 30: 58 pop %rax 31: fa cli 32: f6 c4 02 test $0x2,%ah 35: 75 1e jne 0x55 37: bf 01 00 00 00 mov $0x1,%edi 3c: e8 .byte 0xe8 3d: 6d insl (%dx),%es:(%rdi) 3e: 39 .byte 0x39 3f: 88 .byte 0x88