======================================================== WARNING: possible irq lock inversion dependency detected 6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted -------------------------------------------------------- syz-executor.0/7286 just changed the state of lock: ffff888029d56148 (&timer->lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] ffff888029d56148 (&timer->lock){+.+.}-{2:2}, at: class_spinlock_constructor include/linux/spinlock.h:561 [inline] ffff888029d56148 (&timer->lock){+.+.}-{2:2}, at: snd_timer_close_locked+0x65/0xbd0 sound/core/timer.c:412 but this lock was taken by another, SOFTIRQ-safe lock in the past: (&group->lock#2){..-.}-{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 syz-executor.0/7286: #0: ffff88805b0499d0 (&client->ioctl_mutex){+.+.}-{3:3}, at: snd_seq_ioctl+0x1f7/0x3f0 sound/core/seq/seq_clientmgr.c:2326 #1: ffff8880794b1578 (&q->timer_mutex){+.+.}-{3:3}, at: snd_seq_ioctl_set_queue_timer+0x129/0x450 sound/core/seq/seq_clientmgr.c:1793 #2: ffffffff8f1c72c8 (register_mutex){+.+.}-{3:3}, at: class_mutex_constructor include/linux/mutex.h:169 [inline] #2: ffffffff8f1c72c8 (register_mutex){+.+.}-{3:3}, at: snd_timer_close+0x7e/0xf0 sound/core/timer.c:463 the shortest dependencies between 2nd lock and 1st lock: -> (&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+0x1a3/0x5b0 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+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 arch_stack_walk+0xdb/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_record_aux_stack+0xba/0xd0 mm/kasan/generic.c:541 __call_rcu_common.constprop.0+0x9a/0x790 kernel/rcu/tree.c:2734 dentry_free+0xc2/0x160 fs/dcache.c:376 __dentry_kill+0x498/0x600 fs/dcache.c:622 dput.part.0+0x4b1/0x9b0 fs/dcache.c:845 dput+0x1f/0x30 fs/dcache.c:835 lookup_fast+0x27f/0x540 fs/namei.c:1658 walk_component+0x5b/0x5b0 fs/namei.c:2000 lookup_last fs/namei.c:2461 [inline] path_lookupat+0x17f/0x770 fs/namei.c:2485 filename_lookup+0x1e5/0x5b0 fs/namei.c:2514 vfs_statx+0x13e/0x550 fs/stat.c:244 vfs_fstatat+0xb3/0x150 fs/stat.c:304 __do_sys_newfstatat+0x98/0x120 fs/stat.c:468 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: __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+0x10d/0x150 sound/core/pcm_native.c:1289 snd_pcm_action+0x70/0x90 sound/core/pcm_native.c:1370 __snd_pcm_lib_xfer+0x13f5/0x1ea0 sound/core/pcm_lib.c:2371 snd_pcm_lib_write include/sound/pcm.h:1166 [inline] snd_pcm_write+0x184/0x260 sound/core/pcm_native.c:3497 vfs_write+0x29b/0x1100 fs/read_write.c:588 ksys_write+0x12f/0x260 fs/read_write.c:643 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 -> (&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 snd_seq_queue_timer_close+0x28/0x60 sound/core/seq/seq_queue.c:444 snd_seq_ioctl_set_queue_timer+0x17d/0x450 sound/core/seq/seq_clientmgr.c:1795 snd_seq_ioctl+0x225/0x3f0 sound/core/seq/seq_clientmgr.c:2327 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 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 snd_seq_queue_timer_close+0x28/0x60 sound/core/seq/seq_queue.c:444 snd_seq_ioctl_set_queue_timer+0x17d/0x450 sound/core/seq/seq_clientmgr.c:1795 snd_seq_ioctl+0x225/0x3f0 sound/core/seq/seq_clientmgr.c:2327 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 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+0x10d/0x150 sound/core/pcm_native.c:1289 snd_pcm_action+0x70/0x90 sound/core/pcm_native.c:1370 __snd_pcm_lib_xfer+0x13f5/0x1ea0 sound/core/pcm_lib.c:2371 snd_pcm_lib_write include/sound/pcm.h:1166 [inline] snd_pcm_write+0x184/0x260 sound/core/pcm_native.c:3497 vfs_write+0x29b/0x1100 fs/read_write.c:588 ksys_write+0x12f/0x260 fs/read_write.c:643 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: mark_usage kernel/locking/lockdep.c:4591 [inline] __lock_acquire+0x979/0x3b30 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 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 snd_seq_queue_timer_close+0x28/0x60 sound/core/seq/seq_queue.c:444 snd_seq_ioctl_set_queue_timer+0x17d/0x450 sound/core/seq/seq_clientmgr.c:1795 snd_seq_ioctl+0x225/0x3f0 sound/core/seq/seq_clientmgr.c:2327 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 stack backtrace: CPU: 0 PID: 7286 Comm: syz-executor.0 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:4591 [inline] __lock_acquire+0x979/0x3b30 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 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 snd_seq_queue_timer_close+0x28/0x60 sound/core/seq/seq_queue.c:444 snd_seq_ioctl_set_queue_timer+0x17d/0x450 sound/core/seq/seq_clientmgr.c:1795 snd_seq_ioctl+0x225/0x3f0 sound/core/seq/seq_clientmgr.c:2327 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 RIP: 0033:0x7f0848c7de69 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f08487ff0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f0848dabf80 RCX: 00007f0848c7de69 RDX: 0000000020000280 RSI: 0000000040605346 RDI: 0000000000000004 RBP: 00007f0848cca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f0848dabf80 R15: 00007fff6b060a08 ALSA: seq fatal error: cannot create timer (-22)