R13: 00000000000004a7 R14: 00000000006fb048 R15: 0000000000000002 kasan: CONFIG_KASAN_INLINE enabled kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 13905 Comm: udevd Not tainted 4.17.0-rc3+ #31 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:perf_tp_event_match kernel/events/core.c:8235 [inline] RIP: 0010:perf_tp_event+0x427/0xc30 kernel/events/core.c:8286 RSP: 0018:ffff8801acea7380 EFLAGS: 00010002 RAX: 000006ca2060204a RBX: 0000365103010080 RCX: ffffffff81921715 RDX: 0000000000000000 RSI: ffffffff819217a9 RDI: 0000365103010250 RBP: ffff8801acea77b0 R08: ffff8801d7e4c200 R09: ffff8801dae00000 R10: ffff8801acea77e0 R11: 0000000000000000 R12: ffffed00359d4e90 R13: dffffc0000000000 R14: ffff8801acea75c0 R15: dffffc0000000000 FS: 00007fb9286417a0(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb928648000 CR3: 00000001aec72000 CR4: 00000000001406f0 DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: perf_trace_run_bpf_submit+0x23f/0x370 kernel/events/core.c:8261 perf_trace_sched_wakeup_template+0x4fc/0x910 include/trace/events/sched.h:57 trace_sched_wakeup_new include/trace/events/sched.h:103 [inline] wake_up_new_task+0x7ad/0xc10 kernel/sched/core.c:2447 _do_fork+0x379/0x12a0 kernel/fork.c:2113 __do_sys_clone kernel/fork.c:2195 [inline] __se_sys_clone kernel/fork.c:2189 [inline] __x64_sys_clone+0xbf/0x150 kernel/fork.c:2189 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fb927d24f46 RSP: 002b:00007ffe709c6b80 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffe709c6b80 RCX: 00007fb927d24f46 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffe709c6be0 R08: 0000000000003651 R09: 0000000000003651 R10: 00007fb928641a70 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe709c6ba0 R14: 0000000000000005 R15: 0000000000000005 Code: 48 85 db 0f 84 da 00 00 00 e8 a6 27 e7 ff 48 83 eb 60 0f 84 cb 00 00 00 e8 97 27 e7 ff 48 8d bb d0 01 00 00 48 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 74 08 3c 03 0f 8e dc 06 00 00 44 8b bb d0 RIP: perf_tp_event_match kernel/events/core.c:8235 [inline] RSP: ffff8801acea7380 RIP: perf_tp_event+0x427/0xc30 kernel/events/core.c:8286 RSP: ffff8801acea7380 ====================================================== WARNING: possible circular locking dependency detected 4.17.0-rc3+ #31 Not tainted ------------------------------------------------------ udevd/13905 is trying to acquire lock: 000000003dcbb218 ((console_sem).lock){-.-.}, at: down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 but task is already holding lock: 000000008f208626 (&rq->lock){-.-.}, at: __task_rq_lock+0xe0/0x300 kernel/sched/core.c:77 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&rq->lock){-.-.}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144 rq_lock kernel/sched/sched.h:1799 [inline] task_fork_fair+0x8a/0x660 kernel/sched/fair.c:9967 sched_fork+0x43e/0xb30 kernel/sched/core.c:2379 copy_process.part.38+0x1c18/0x6e90 kernel/fork.c:1764 copy_process kernel/fork.c:1607 [inline] _do_fork+0x291/0x12a0 kernel/fork.c:2088 kernel_thread+0x34/0x40 kernel/fork.c:2147 rest_init+0x22/0xe4 init/main.c:407 start_kernel+0x906/0x92d init/main.c:737 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:445 x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:426 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242 -> #1 (&p->pi_lock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152 try_to_wake_up+0xca/0x1190 kernel/sched/core.c:1963 wake_up_process+0x10/0x20 kernel/sched/core.c:2126 __up.isra.1+0x1b8/0x290 kernel/locking/semaphore.c:262 up+0x12f/0x1b0 kernel/locking/semaphore.c:187 __up_console_sem+0xbe/0x1b0 kernel/printk/printk.c:242 console_unlock+0x7d6/0x1100 kernel/printk/printk.c:2417 do_con_write+0x12b2/0x2280 drivers/tty/vt/vt.c:2437 con_write+0x25/0xc0 drivers/tty/vt/vt.c:2786 process_output_block drivers/tty/n_tty.c:579 [inline] n_tty_write+0x6b9/0x1180 drivers/tty/n_tty.c:2308 do_tty_write drivers/tty/tty_io.c:958 [inline] tty_write+0x3f1/0x880 drivers/tty/tty_io.c:1042 __vfs_write+0x10b/0x960 fs/read_write.c:485 vfs_write+0x1f8/0x560 fs/read_write.c:549 ksys_write+0xf9/0x250 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 ((console_sem).lock){-.-.}: lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 __down_trylock_console_sem+0xae/0x200 kernel/printk/printk.c:225 console_trylock+0x15/0xa0 kernel/printk/printk.c:2229 console_trylock_spinning kernel/printk/printk.c:1643 [inline] vprintk_emit+0x694/0xdd0 kernel/printk/printk.c:1906 vprintk_default+0x28/0x30 kernel/printk/printk.c:1947 vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:379 printk+0x9e/0xba kernel/printk/printk.c:1980 kasan_die_handler.cold.22+0x11/0x30 arch/x86/mm/kasan_init_64.c:253 notifier_call_chain+0x178/0x380 kernel/notifier.c:93 __atomic_notifier_call_chain kernel/notifier.c:183 [inline] atomic_notifier_call_chain+0x98/0x190 kernel/notifier.c:193 notify_die+0x1a3/0x2b0 kernel/notifier.c:549 do_general_protection+0x248/0x2f0 arch/x86/kernel/traps.c:558 general_protection+0x1e/0x30 arch/x86/entry/entry_64.S:1159 perf_tp_event_match kernel/events/core.c:8235 [inline] perf_tp_event+0x427/0xc30 kernel/events/core.c:8286 perf_trace_run_bpf_submit+0x23f/0x370 kernel/events/core.c:8261 perf_trace_sched_wakeup_template+0x4fc/0x910 include/trace/events/sched.h:57 trace_sched_wakeup_new include/trace/events/sched.h:103 [inline] wake_up_new_task+0x7ad/0xc10 kernel/sched/core.c:2447 _do_fork+0x379/0x12a0 kernel/fork.c:2113 __do_sys_clone kernel/fork.c:2195 [inline] __se_sys_clone kernel/fork.c:2189 [inline] __x64_sys_clone+0xbf/0x150 kernel/fork.c:2189 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: (console_sem).lock --> &p->pi_lock --> &rq->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->lock); lock(&p->pi_lock); lock(&rq->lock); lock((console_sem).lock); *** DEADLOCK *** 3 locks held by udevd/13905: #0: 00000000e1d7c5c3 (&p->pi_lock){-.-.}, at: wake_up_new_task+0xa1/0xc10 kernel/sched/core.c:2427 #1: 000000008f208626 (&rq->lock){-.-.}, at: __task_rq_lock+0xe0/0x300 kernel/sched/core.c:77 #2: 0000000081b0555b (rcu_read_lock){....}, at: atomic_notifier_call_chain+0x0/0x190 include/linux/compiler.h:188 stack backtrace: CPU: 0 PID: 13905 Comm: udevd Not tainted 4.17.0-rc3+ #31 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b9/0x294 lib/dump_stack.c:113 print_circular_bug.isra.36.cold.54+0x1bd/0x27d kernel/locking/lockdep.c:1223 check_prev_add kernel/locking/lockdep.c:1863 [inline] check_prevs_add kernel/locking/lockdep.c:1976 [inline] validate_chain kernel/locking/lockdep.c:2417 [inline] __lock_acquire+0x343e/0x5140 kernel/locking/lockdep.c:3431 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:152 down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 __down_trylock_console_sem+0xae/0x200 kernel/printk/printk.c:225 console_trylock+0x15/0xa0 kernel/printk/printk.c:2229 console_trylock_spinning kernel/printk/printk.c:1643 [inline] vprintk_emit+0x694/0xdd0 kernel/printk/printk.c:1906 vprintk_default+0x28/0x30 kernel/printk/printk.c:1947 vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:379 printk+0x9e/0xba kernel/printk/printk.c:1980 kasan_die_handler.cold.22+0x11/0x30 arch/x86/mm/kasan_init_64.c:253 notifier_call_chain+0x178/0x380 kernel/notifier.c:93 __atomic_notifier_call_chain kernel/notifier.c:183 [inline] atomic_notifier_call_chain+0x98/0x190 kernel/notifier.c:193 notify_die+0x1a3/0x2b0 kernel/notifier.c:549 do_general_protection+0x248/0x2f0 arch/x86/kernel/traps.c:558 general_protection+0x1e/0x30 arch/x86/entry/entry_64.S:1159 RIP: 0010:perf_tp_event_match kernel/events/core.c:8235 [inline] RIP: 0010:perf_tp_event+0x427/0xc30 kernel/events/core.c:8286 RSP: 0018:ffff8801acea7380 EFLAGS: 00010002 RAX: 000006ca2060204a RBX: 0000365103010080 RCX: ffffffff81921715 RDX: 0000000000000000 RSI: ffffffff819217a9 RDI: 0000365103010250 RBP: ffff8801acea77b0 R08: ffff8801d7e4c200 R09: ffff8801dae00000 R10: ffff8801acea77e0 R11: 0000000000000000 R12: ffffed00359d4e90 R13: dffffc0000000000 R14: ffff8801acea75c0 R15: dffffc0000000000 perf_trace_run_bpf_submit+0x23f/0x370 kernel/events/core.c:8261 perf_trace_sched_wakeup_template+0x4fc/0x910 include/trace/events/sched.h:57 trace_sched_wakeup_new include/trace/events/sched.h:103 [inline] wake_up_new_task+0x7ad/0xc10 kernel/sched/core.c:2447 _do_fork+0x379/0x12a0 kernel/fork.c:2113 __do_sys_clone kernel/fork.c:2195 [inline] __se_sys_clone kernel/fork.c:2189 [inline] __x64_sys_clone+0xbf/0x150 kernel/fork.c:2189 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fb927d24f46 RSP: 002b:00007ffe709c6b80 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffe709c6b80 RCX: 00007fb927d24f46 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffe709c6be0 R08: 0000000000003651 R09: 0000000000003651 R10: 00007fb928641a70 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe709c6ba0 R14: 0000000000000005 R15: 0000000000000005 ---[ end trace a533ec42f4e51501 ]--- general protection fault: 0000 [#2] SMP KASAN Dumping ftrace buffer: