======================================================== WARNING: possible irq lock inversion dependency detected 5.14.0-rc4-syzkaller #0 Not tainted -------------------------------------------------------- syz-executor.4/16059 just changed the state of lock: ffff888147959948 (&timer->lock){..-.}-{2:2}, at: snd_timer_interrupt.part.0+0x34/0xcf0 sound/core/timer.c:857 but this lock took another, SOFTIRQ-READ-unsafe lock in the past: (&new->fa_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(&new->fa_lock); local_irq_disable(); lock(&timer->lock); lock(&new->fa_lock); lock(&timer->lock); *** DEADLOCK *** 1 lock held by syz-executor.4/16059: #0: ffffc9000138fcb8 ((&priv->tlist)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:35 [inline] #0: ffffc9000138fcb8 ((&priv->tlist)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 kernel/time/timer.c:1409 the shortest dependencies between 2nd lock and 1st lock: -> (&new->fa_lock){.+.+}-{2:2} { HARDIRQ-ON-R at: lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync fs/fcntl.c:1033 [inline] kill_fasync+0x132/0x460 fs/fcntl.c:1026 lease_break_callback+0x1f/0x30 fs/locks.c:585 __break_lease+0x3d9/0x1420 fs/locks.c:1657 break_lease include/linux/fs.h:2668 [inline] break_lease include/linux/fs.h:2658 [inline] do_dentry_open+0x453/0x11d0 fs/open.c:817 do_open fs/namei.c:3374 [inline] path_openat+0x1c23/0x27f0 fs/namei.c:3507 do_filp_open+0x1aa/0x400 fs/namei.c:3534 do_sys_openat2+0x16d/0x420 fs/open.c:1204 do_sys_open fs/open.c:1220 [inline] __do_sys_open fs/open.c:1228 [inline] __se_sys_open fs/open.c:1224 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1224 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae SOFTIRQ-ON-R at: lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync fs/fcntl.c:1033 [inline] kill_fasync+0x132/0x460 fs/fcntl.c:1026 lease_break_callback+0x1f/0x30 fs/locks.c:585 __break_lease+0x3d9/0x1420 fs/locks.c:1657 break_lease include/linux/fs.h:2668 [inline] break_lease include/linux/fs.h:2658 [inline] do_dentry_open+0x453/0x11d0 fs/open.c:817 do_open fs/namei.c:3374 [inline] path_openat+0x1c23/0x27f0 fs/namei.c:3507 do_filp_open+0x1aa/0x400 fs/namei.c:3534 do_sys_openat2+0x16d/0x420 fs/open.c:1204 do_sys_open fs/open.c:1220 [inline] __do_sys_open fs/open.c:1228 [inline] __se_sys_open fs/open.c:1224 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1224 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_write_lock_irq include/linux/rwlock_api_smp.h:196 [inline] _raw_write_lock_irq+0x32/0x50 kernel/locking/spinlock.c:311 fasync_remove_entry+0xb6/0x1f0 fs/fcntl.c:890 fasync_helper+0x9e/0xb0 fs/fcntl.c:993 sg_fasync+0xe6/0x1c0 drivers/scsi/sg.c:1240 __fput+0x712/0x920 fs/file_table.c:277 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae INITIAL READ USE at: lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync fs/fcntl.c:1033 [inline] kill_fasync+0x132/0x460 fs/fcntl.c:1026 lease_break_callback+0x1f/0x30 fs/locks.c:585 __break_lease+0x3d9/0x1420 fs/locks.c:1657 break_lease include/linux/fs.h:2668 [inline] break_lease include/linux/fs.h:2658 [inline] do_dentry_open+0x453/0x11d0 fs/open.c:817 do_open fs/namei.c:3374 [inline] path_openat+0x1c23/0x27f0 fs/namei.c:3507 do_filp_open+0x1aa/0x400 fs/namei.c:3534 do_sys_openat2+0x16d/0x420 fs/open.c:1204 do_sys_open fs/open.c:1220 [inline] __do_sys_open fs/open.c:1228 [inline] __se_sys_open fs/open.c:1224 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1224 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae } ... key at: [] __key.0+0x0/0x40 ... acquired at: __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x5b/0x70 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync fs/fcntl.c:1033 [inline] kill_fasync+0x132/0x460 fs/fcntl.c:1026 snd_timer_user_ccallback+0x298/0x330 sound/core/timer.c:1387 snd_timer_notify1+0x11c/0x3b0 sound/core/timer.c:516 snd_timer_start1+0x4d4/0x800 sound/core/timer.c:578 snd_timer_start sound/core/timer.c:697 [inline] snd_timer_start sound/core/timer.c:690 [inline] snd_timer_user_start.isra.0+0x1e3/0x260 sound/core/timer.c:1985 __snd_timer_user_ioctl.isra.0+0xda8/0x24c0 sound/core/timer.c:2108 snd_timer_user_ioctl+0x77/0xb0 sound/core/timer.c:2129 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl fs/ioctl.c:1055 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> (&timer->lock){..-.}-{2:2} { IN-SOFTIRQ-W at: lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 snd_timer_interrupt.part.0+0x34/0xcf0 sound/core/timer.c:857 snd_timer_interrupt sound/core/timer.c:1155 [inline] snd_timer_s_function+0x14b/0x200 sound/core/timer.c:1155 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1419 expire_timers kernel/time/timer.c:1464 [inline] __run_timers.part.0+0x675/0xa50 kernel/time/timer.c:1732 __run_timers kernel/time/timer.c:1713 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1745 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x45/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 INITIAL USE at: lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x32/0x50 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:379 [inline] snd_timer_close_locked+0x63/0xbb0 sound/core/timer.c:396 snd_timer_close+0x87/0xf0 sound/core/timer.c:463 snd_seq_timer_close+0x8c/0xe0 sound/core/seq/seq_timer.c:326 queue_delete+0x4a/0xa0 sound/core/seq/seq_queue.c:134 snd_seq_queue_delete+0x45/0x60 sound/core/seq/seq_queue.c:196 snd_seq_kernel_client_ctl+0x102/0x1e0 sound/core/seq/seq_clientmgr.c:2369 delete_seq_queue.part.0.isra.0+0xa2/0x110 sound/core/seq/oss/seq_oss_init.c:377 delete_seq_queue sound/core/seq/oss/seq_oss_init.c:373 [inline] snd_seq_oss_release+0x10b/0x1a0 sound/core/seq/oss/seq_oss_init.c:422 odev_release+0x4f/0x70 sound/core/seq/oss/seq_oss.c:144 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:175 [inline] exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae } ... key at: [] __key.12+0x0/0x40 ... acquired at: mark_usage kernel/locking/lockdep.c:4488 [inline] __lock_acquire+0x11d5/0x54a0 kernel/locking/lockdep.c:4969 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 snd_timer_interrupt.part.0+0x34/0xcf0 sound/core/timer.c:857 snd_timer_interrupt sound/core/timer.c:1155 [inline] snd_timer_s_function+0x14b/0x200 sound/core/timer.c:1155 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1419 expire_timers kernel/time/timer.c:1464 [inline] __run_timers.part.0+0x675/0xa50 kernel/time/timer.c:1732 __run_timers kernel/time/timer.c:1713 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1745 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x45/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 stack backtrace: CPU: 0 PID: 16059 Comm: syz-executor.4 Not tainted 5.14.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105 print_irq_inversion_bug kernel/locking/lockdep.c:203 [inline] check_usage_forwards kernel/locking/lockdep.c:4031 [inline] mark_lock_irq kernel/locking/lockdep.c:4163 [inline] mark_lock.cold+0x86/0x8e kernel/locking/lockdep.c:4593 mark_usage kernel/locking/lockdep.c:4488 [inline] __lock_acquire+0x11d5/0x54a0 kernel/locking/lockdep.c:4969 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 snd_timer_interrupt.part.0+0x34/0xcf0 sound/core/timer.c:857 snd_timer_interrupt sound/core/timer.c:1155 [inline] snd_timer_s_function+0x14b/0x200 sound/core/timer.c:1155 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1419 expire_timers kernel/time/timer.c:1464 [inline] __run_timers.part.0+0x675/0xa50 kernel/time/timer.c:1732 __run_timers kernel/time/timer.c:1713 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1745 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x45/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0033:0x48a7b1 Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 aa e7 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 e3 e7 ff ff 48 8b 04 24 eb 97 66 2e 0f 1f RSP: 002b:0000000000a9fb30 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000050bd1 RCX: 000000000048a7b1 RDX: 0000000000a9fb70 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: 00007fff97b39080 R10: 0000000000000000 R11: 0000000000000293 R12: 000000000056bf80 R13: 000000000056cb00 R14: 000000000056bf80 R15: 0000000000050890