======================================================== WARNING: possible irq lock inversion dependency detected 5.14.0-rc3-syzkaller #0 Not tainted -------------------------------------------------------- systemd-udevd/4862 just changed the state of lock: ffff8881477c4148 (&timer->lock){..-.}-{2:2}, at: snd_timer_interrupt+0x210/0x1410 sound/core/timer.c:857 but this lock took another, SOFTIRQ-READ-unsafe lock in the past: (&f->f_owner.lock){.+.+}-{2:2} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Chain exists of: &timer->lock --> &new->fa_lock --> &f->f_owner.lock Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&f->f_owner.lock); local_irq_disable(); lock(&timer->lock); lock(&new->fa_lock); lock(&timer->lock); *** DEADLOCK *** 2 locks held by systemd-udevd/4862: #0: ffffffff8c7177c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:266 #1: ffffc90000007be0 ((&priv->tlist)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:45 [inline] #1: ffffc90000007be0 ((&priv->tlist)){+.-.}-{0:0}, at: call_timer_fn+0xbd/0x210 kernel/time/timer.c:1409 the shortest dependencies between 2nd lock and 1st lock: -> (&f->f_owner.lock){.+.+}-{2:2} { HARDIRQ-ON-R at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 f_getown+0x22/0x210 fs/fcntl.c:153 sock_ioctl+0x2c6/0x6a0 net/socket.c:1166 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae SOFTIRQ-ON-R at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 f_getown+0x22/0x210 fs/fcntl.c:153 sock_ioctl+0x2c6/0x6a0 net/socket.c:1166 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae INITIAL READ USE at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 f_getown+0x22/0x210 fs/fcntl.c:153 sock_ioctl+0x2c6/0x6a0 net/socket.c:1166 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae } ... key at: [] __alloc_file.__key+0x0/0x10 ... acquired at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:159 [inline] _raw_read_lock_irqsave+0xbb/0x100 kernel/locking/spinlock.c:231 send_sigio+0x2f/0x300 fs/fcntl.c:795 kill_fasync_rcu fs/fcntl.c:1019 [inline] kill_fasync+0x1e3/0x430 fs/fcntl.c:1033 snd_timer_user_ccallback+0x3ee/0x710 sound/core/timer.c:1387 snd_timer_notify1+0x19e/0x340 sound/core/timer.c:516 snd_timer_start1+0x53d/0x640 sound/core/timer.c:578 snd_timer_start sound/core/timer.c:697 [inline] snd_timer_user_start sound/core/timer.c:1985 [inline] __snd_timer_user_ioctl+0xe18/0x5ed0 sound/core/timer.c:2108 snd_timer_user_ioctl+0x5d/0x80 sound/core/timer.c:2129 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> (&new->fa_lock){....}-{2:2} { INITIAL USE at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_write_lock_irq include/linux/rwlock_api_smp.h:196 [inline] _raw_write_lock_irq+0xae/0xf0 kernel/locking/spinlock.c:311 fasync_remove_entry+0xff/0x1d0 fs/fcntl.c:890 __fput+0x65b/0x7b0 fs/file_table.c:277 task_work_run+0x146/0x1c0 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+0x201/0x220 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:302 do_syscall_64+0x4c/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae INITIAL READ USE at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync+0x13b/0x430 fs/fcntl.c:1033 snd_timer_user_ccallback+0x3ee/0x710 sound/core/timer.c:1387 snd_timer_notify1+0x19e/0x340 sound/core/timer.c:516 snd_timer_start1+0x53d/0x640 sound/core/timer.c:578 snd_timer_start sound/core/timer.c:697 [inline] snd_timer_user_start sound/core/timer.c:1985 [inline] __snd_timer_user_ioctl+0xe18/0x5ed0 sound/core/timer.c:2108 snd_timer_user_ioctl+0x5d/0x80 sound/core/timer.c:2129 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae } ... key at: [] fasync_insert_entry.__key+0x0/0x40 ... acquired at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_read_lock include/linux/rwlock_api_smp.h:149 [inline] _raw_read_lock+0x32/0x40 kernel/locking/spinlock.c:223 kill_fasync_rcu fs/fcntl.c:1012 [inline] kill_fasync+0x13b/0x430 fs/fcntl.c:1033 snd_timer_user_ccallback+0x3ee/0x710 sound/core/timer.c:1387 snd_timer_notify1+0x19e/0x340 sound/core/timer.c:516 snd_timer_start1+0x53d/0x640 sound/core/timer.c:578 snd_timer_start sound/core/timer.c:697 [inline] snd_timer_user_start sound/core/timer.c:1985 [inline] __snd_timer_user_ioctl+0xe18/0x5ed0 sound/core/timer.c:2108 snd_timer_user_ioctl+0x5d/0x80 sound/core/timer.c:2129 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae -> (&timer->lock){..-.}-{2:2} { IN-SOFTIRQ-W at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb3/0x100 kernel/locking/spinlock.c:159 snd_timer_interrupt+0x210/0x1410 sound/core/timer.c:857 call_timer_fn+0xf6/0x210 kernel/time/timer.c:1419 expire_timers kernel/time/timer.c:1464 [inline] __run_timers+0x6ff/0x910 kernel/time/timer.c:1732 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1745 __do_softirq+0x372/0x783 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x21b/0x260 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 lock_acquire+0x1e7/0x4a0 kernel/locking/lockdep.c:5629 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:267 rcu_read_lock include/linux/rcupdate.h:687 [inline] dput+0x58/0x6e0 fs/dcache.c:874 path_put+0x35/0x60 fs/namei.c:546 do_faccessat+0x6b6/0x910 fs/open.c:459 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae INITIAL USE at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb3/0x100 kernel/locking/spinlock.c:159 snd_timer_resolution sound/core/timer.c:489 [inline] snd_timer_user_params sound/core/timer.c:1852 [inline] __snd_timer_user_ioctl+0x1df7/0x5ed0 sound/core/timer.c:2101 snd_timer_user_ioctl+0x5d/0x80 sound/core/timer.c:2129 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae } ... key at: [] snd_timer_new.__key+0x0/0x40 ... acquired at: mark_usage kernel/locking/lockdep.c:4488 [inline] __lock_acquire+0xca1/0x6100 kernel/locking/lockdep.c:4969 lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb3/0x100 kernel/locking/spinlock.c:159 snd_timer_interrupt+0x210/0x1410 sound/core/timer.c:857 call_timer_fn+0xf6/0x210 kernel/time/timer.c:1419 expire_timers kernel/time/timer.c:1464 [inline] __run_timers+0x6ff/0x910 kernel/time/timer.c:1732 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1745 __do_softirq+0x372/0x783 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x21b/0x260 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 lock_acquire+0x1e7/0x4a0 kernel/locking/lockdep.c:5629 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:267 rcu_read_lock include/linux/rcupdate.h:687 [inline] dput+0x58/0x6e0 fs/dcache.c:874 path_put+0x35/0x60 fs/namei.c:546 do_faccessat+0x6b6/0x910 fs/open.c:459 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae stack backtrace: CPU: 0 PID: 4862 Comm: systemd-udevd Not tainted 5.14.0-rc3-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+0x1ae/0x29f lib/dump_stack.c:105 print_irq_inversion_bug+0xa58/0xda0 kernel/locking/lockdep.c:4000 check_usage_forwards kernel/locking/lockdep.c:2585 [inline] mark_lock_irq kernel/locking/lockdep.c:4163 [inline] mark_lock+0x1064/0x1eb0 kernel/locking/lockdep.c:4593 mark_usage kernel/locking/lockdep.c:4488 [inline] __lock_acquire+0xca1/0x6100 kernel/locking/lockdep.c:4969 lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb3/0x100 kernel/locking/spinlock.c:159 snd_timer_interrupt+0x210/0x1410 sound/core/timer.c:857 call_timer_fn+0xf6/0x210 kernel/time/timer.c:1419 expire_timers kernel/time/timer.c:1464 [inline] __run_timers+0x6ff/0x910 kernel/time/timer.c:1732 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1745 __do_softirq+0x372/0x783 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x21b/0x260 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lock_acquire+0x1e7/0x4a0 kernel/locking/lockdep.c:5629 Code: 08 48 89 df e8 ba 6b 67 00 f6 84 24 81 00 00 00 02 0f 85 24 02 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 04 2c 00 00 00 00 43 c7 44 2c 09 00 00 00 00 43 c7 44 2c 11 RSP: 0018:ffffc9000115fc40 EFLAGS: 00000206 RAX: 1ffff9200022bf98 RBX: ffffc9000115fcc0 RCX: ffffffff81621415 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000115fda0 R08: dffffc0000000000 R09: fffffbfff1f5e5b1 R10: fffffbfff1f5e5b1 R11: 0000000000000000 R12: dffffc0000000000 R13: 1ffff9200022bf90 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:267 rcu_read_lock include/linux/rcupdate.h:687 [inline] dput+0x58/0x6e0 fs/dcache.c:874 path_put+0x35/0x60 fs/namei.c:546 do_faccessat+0x6b6/0x910 fs/open.c:459 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f7a97ad29c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd448f6a28 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 000055d863202230 RCX: 00007f7a97ad29c7 RDX: 00746e657665752f RSI: 0000000000000000 RDI: 00007ffd448f6a30 RBP: 00007ffd448f6aa0 R08: 000000000000ffff R09: 0000000000001000 R10: 0000000000000020 R11: 0000000000000246 R12: 000055d861bc9856 R13: 000055d863207e90 R14: 00007ffd448f6a30 R15: 00007ffd448f7c70