======================================================== WARNING: possible irq lock inversion dependency detected 5.14.0-rc2-syzkaller #0 Not tainted -------------------------------------------------------- kworker/u4:3/138 just changed the state of lock: ffff8881475ff908 (&group->lock){..-.}-{2:2}, at: snd_pcm_period_elapsed+0x2c/0x210 sound/core/pcm_lib.c:1847 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: &group->lock --> &timer->lock --> &f->f_owner.lock Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&f->f_owner.lock); local_irq_disable(); lock(&group->lock); lock(&timer->lock); lock(&group->lock); *** DEADLOCK *** 4 locks held by kworker/u4:3/138: #0: ffff8881443db138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7aa/0x10c0 kernel/workqueue.c:2249 #1: ffffc9000147fd20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7e8/0x10c0 kernel/workqueue.c:2251 #2: ffffffff8d73a6f0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf0/0xc60 net/core/net_namespace.c:557 #3: ffffffff8c7177c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:266 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 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 f_modown+0x38/0x340 fs/fcntl.c:91 __f_setown fs/fcntl.c:110 [inline] f_setown+0x113/0x1a0 fs/fcntl.c:138 sock_ioctl+0x27b/0x6a0 net/socket.c:1162 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} { 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_notify+0x105/0x3e0 sound/core/timer.c:1087 snd_pcm_timer_notify sound/core/pcm_native.c:587 [inline] snd_pcm_post_stop sound/core/pcm_native.c:1445 [inline] snd_pcm_action_single sound/core/pcm_native.c:1221 [inline] snd_pcm_action sound/core/pcm_native.c:1302 [inline] snd_pcm_stop+0x3b8/0x4c0 sound/core/pcm_native.c:1468 snd_pcm_drop+0x16d/0x290 sound/core/pcm_native.c:2147 snd_pcm_oss_sync+0x4f4/0xee0 sound/core/oss/pcm_oss.c:1721 snd_pcm_oss_release+0x119/0x270 sound/core/oss/pcm_oss.c:2571 __fput+0x352/0x7b0 fs/file_table.c:280 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 } ... key at: [] snd_timer_new.__key+0x0/0x40 ... acquired 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_notify+0x105/0x3e0 sound/core/timer.c:1087 snd_pcm_timer_notify sound/core/pcm_native.c:587 [inline] snd_pcm_post_stop sound/core/pcm_native.c:1445 [inline] snd_pcm_action_single sound/core/pcm_native.c:1221 [inline] snd_pcm_action sound/core/pcm_native.c:1302 [inline] snd_pcm_stop+0x3b8/0x4c0 sound/core/pcm_native.c:1468 snd_pcm_drop+0x16d/0x290 sound/core/pcm_native.c:2147 snd_pcm_oss_sync+0x4f4/0xee0 sound/core/oss/pcm_oss.c:1721 snd_pcm_oss_release+0x119/0x270 sound/core/oss/pcm_oss.c:2571 __fput+0x352/0x7b0 fs/file_table.c:280 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 -> (&group->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_pcm_period_elapsed+0x2c/0x210 sound/core/pcm_lib.c:1847 dummy_hrtimer_callback+0x87/0x190 sound/drivers/dummy.c:377 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x50b/0xa60 kernel/time/hrtimer.c:1601 hrtimer_run_softirq+0x176/0x1e0 kernel/time/hrtimer.c:1618 __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] inet_twsk_purge+0x11b/0x890 net/ipv4/inet_timewait_sock.c:268 ops_exit_list net/core/net_namespace.c:178 [inline] cleanup_net+0x7ec/0xc60 net/core/net_namespace.c:595 process_one_work+0x833/0x10c0 kernel/workqueue.c:2276 worker_thread+0xac1/0x1320 kernel/workqueue.c:2422 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INITIAL USE at: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5625 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0xae/0xf0 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:379 [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] snd_pcm_hw_params+0xca/0x1740 sound/core/pcm_native.c:678 snd_pcm_oss_change_params_locked+0x245a/0x4390 sound/core/oss/pcm_oss.c:947 snd_pcm_oss_change_params sound/core/oss/pcm_oss.c:1091 [inline] snd_pcm_oss_make_ready sound/core/oss/pcm_oss.c:1150 [inline] snd_pcm_oss_sync+0x37c/0xee0 sound/core/oss/pcm_oss.c:1717 snd_pcm_oss_release+0x119/0x270 sound/core/oss/pcm_oss.c:2571 __fput+0x352/0x7b0 fs/file_table.c:280 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 } ... key at: [] snd_pcm_group_init.__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_pcm_period_elapsed+0x2c/0x210 sound/core/pcm_lib.c:1847 dummy_hrtimer_callback+0x87/0x190 sound/drivers/dummy.c:377 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x50b/0xa60 kernel/time/hrtimer.c:1601 hrtimer_run_softirq+0x176/0x1e0 kernel/time/hrtimer.c:1618 __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] inet_twsk_purge+0x11b/0x890 net/ipv4/inet_timewait_sock.c:268 ops_exit_list net/core/net_namespace.c:178 [inline] cleanup_net+0x7ec/0xc60 net/core/net_namespace.c:595 process_one_work+0x833/0x10c0 kernel/workqueue.c:2276 worker_thread+0xac1/0x1320 kernel/workqueue.c:2422 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 stack backtrace: CPU: 0 PID: 138 Comm: kworker/u4:3 Not tainted 5.14.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net 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_pcm_period_elapsed+0x2c/0x210 sound/core/pcm_lib.c:1847 dummy_hrtimer_callback+0x87/0x190 sound/drivers/dummy.c:377 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x50b/0xa60 kernel/time/hrtimer.c:1601 hrtimer_run_softirq+0x176/0x1e0 kernel/time/hrtimer.c:1618 __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 ea 60 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:ffffc9000147f8e0 EFLAGS: 00000206 RAX: 1ffff9200028ff2c RBX: ffffc9000147f960 RCX: ffffffff816213c5 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000147fa40 R08: dffffc0000000000 R09: fffffbfff1f5e1b1 R10: fffffbfff1f5e1b1 R11: 0000000000000000 R12: dffffc0000000000 R13: 1ffff9200028ff24 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:267 rcu_read_lock include/linux/rcupdate.h:687 [inline] inet_twsk_purge+0x11b/0x890 net/ipv4/inet_timewait_sock.c:268 ops_exit_list net/core/net_namespace.c:178 [inline] cleanup_net+0x7ec/0xc60 net/core/net_namespace.c:595 process_one_work+0x833/0x10c0 kernel/workqueue.c:2276 worker_thread+0xac1/0x1320 kernel/workqueue.c:2422 kthread+0x453/0x480 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295