WARNING: CPU: 0 PID: 5344 at kernel/events/core.c:331 event_function_local.constprop.113+0x520/0x5c0 kernel/events/core.c:331 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 5344 Comm: syz-executor5 Not tainted 4.17.0-rc3+ #5 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 panic+0x22f/0x4de kernel/panic.c:184 __warn.cold.8+0x163/0x1b3 kernel/panic.c:536 report_bug+0x252/0x2d0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] do_error_trap+0x1de/0x490 arch/x86/kernel/traps.c:296 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992 RIP: 0010:event_function_local.constprop.113+0x520/0x5c0 kernel/events/core.c:331 RSP: 0018:ffff8801dae07cf8 EFLAGS: 00010006 RAX: ffff8801c335a600 RBX: ffff8801b7025d00 RCX: ffffffff818fdefa RDX: 0000000000010000 RSI: ffffffff818fe0f0 RDI: 0000000000000005 RBP: ffff8801dae07d98 R08: ffff8801c335a600 R09: ffffed0036e04ba1 R10: ffffed0036e04ba1 R11: ffff8801b7025d0b R12: 1ffff1003b5c0fa2 R13: ffff8801dae31408 R14: ffff8801c893e5c0 R15: ffff8801b917a2c0 perf_event_disable_local kernel/events/core.c:2180 [inline] perf_pending_event+0x242/0x2a0 kernel/events/core.c:5809 irq_work_run_list+0x1b4/0x270 kernel/irq_work.c:155 irq_work_run+0x1d/0x50 kernel/irq_work.c:170 smp_irq_work_interrupt+0x10a/0x650 arch/x86/kernel/irq_work.c:21 irq_work_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:783 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa1/0xc0 kernel/locking/spinlock.c:184 RSP: 0018:ffff880197e6f618 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff09 RAX: dffffc0000000000 RBX: 0000000000000286 RCX: 0000000000000000 RDX: 1ffffffff11a316d RSI: ffff8801c335ae38 RDI: 0000000000000286 RBP: ffff880197e6f628 R08: ffff8801c335ae38 R09: 0000000000000006 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d8c57300 R13: 0000000000000001 R14: ffff880197e6f718 R15: 0000000000000286 spin_unlock_irqrestore include/linux/spinlock.h:365 [inline] __wake_up_common_lock+0x1c2/0x300 kernel/sched/wait.c:120 __wake_up_sync_key+0x19/0x20 kernel/sched/wait.c:197 sock_def_readable+0x249/0x710 net/core/sock.c:2705 unix_stream_sendmsg+0x5ef/0xd20 net/unix/af_unix.c:1901 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:639 ___sys_sendmsg+0x805/0x940 net/socket.c:2117 __sys_sendmsg+0x115/0x270 net/socket.c:2155 __do_sys_sendmsg net/socket.c:2164 [inline] __se_sys_sendmsg net/socket.c:2162 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2162 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455979 RSP: 002b:00007f9f1d9cfc68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f9f1d9d06d4 RCX: 0000000000455979 RDX: 0000000000000000 RSI: 0000000020001440 RDI: 0000000000000015 RBP: 000000000072bf50 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000051a R14: 00000000006fbb10 R15: 0000000000000001 ====================================================== WARNING: possible circular locking dependency detected 4.17.0-rc3+ #5 Not tainted ------------------------------------------------------ syz-executor5/5344 is trying to acquire lock: (ptrval) ((console_sem).lock){-...}, at: down_trylock+0x13/0x70 kernel/locking/semaphore.c:136 but task is already holding lock: (ptrval) (&ctx->lock){-...}, at: perf_ctx_lock kernel/events/core.c:157 [inline] (ptrval) (&ctx->lock){-...}, at: event_function_local.constprop.113+0x2a3/0x5c0 kernel/events/core.c:318 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&ctx->lock){-...}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:144 perf_event_context_sched_out kernel/events/core.c:3129 [inline] __perf_event_task_sched_out+0x12df/0x1a30 kernel/events/core.c:3221 perf_event_task_sched_out include/linux/perf_event.h:1103 [inline] prepare_task_switch kernel/sched/core.c:2636 [inline] context_switch kernel/sched/core.c:2813 [inline] __schedule+0xfed/0x1e30 kernel/sched/core.c:3490 schedule+0xef/0x430 kernel/sched/core.c:3549 freezable_schedule include/linux/freezer.h:172 [inline] futex_wait_queue_me+0x3e8/0x820 kernel/futex.c:2530 futex_wait+0x450/0x9f0 kernel/futex.c:2645 do_futex+0x336/0x27d0 kernel/futex.c:3527 __do_sys_futex kernel/futex.c:3587 [inline] __se_sys_futex kernel/futex.c:3555 [inline] __x64_sys_futex+0x46a/0x680 kernel/futex.c:3555 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #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 con_flush_chars drivers/tty/vt/vt.c:2867 [inline] con_write+0x9e/0xc0 drivers/tty/vt/vt.c:2787 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 __warn.cold.8+0x73/0x1b3 kernel/panic.c:518 report_bug+0x252/0x2d0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] do_error_trap+0x1de/0x490 arch/x86/kernel/traps.c:296 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992 event_function_local.constprop.113+0x520/0x5c0 kernel/events/core.c:331 perf_event_disable_local kernel/events/core.c:2180 [inline] perf_pending_event+0x242/0x2a0 kernel/events/core.c:5809 irq_work_run_list+0x1b4/0x270 kernel/irq_work.c:155 irq_work_run+0x1d/0x50 kernel/irq_work.c:170 smp_irq_work_interrupt+0x10a/0x650 arch/x86/kernel/irq_work.c:21 irq_work_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 arch_local_irq_restore arch/x86/include/asm/paravirt.h:783 [inline] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irqrestore+0xa1/0xc0 kernel/locking/spinlock.c:184 spin_unlock_irqrestore include/linux/spinlock.h:365 [inline] __wake_up_common_lock+0x1c2/0x300 kernel/sched/wait.c:120 __wake_up_sync_key+0x19/0x20 kernel/sched/wait.c:197 sock_def_readable+0x249/0x710 net/core/sock.c:2705 unix_stream_sendmsg+0x5ef/0xd20 net/unix/af_unix.c:1901 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:639 ___sys_sendmsg+0x805/0x940 net/socket.c:2117 __sys_sendmsg+0x115/0x270 net/socket.c:2155 __do_sys_sendmsg net/socket.c:2164 [inline] __se_sys_sendmsg net/socket.c:2162 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2162 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 --> &rq->lock --> &ctx->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ctx->lock); lock(&rq->lock); lock(&ctx->lock); lock((console_sem).lock); *** DEADLOCK *** 3 locks held by syz-executor5/5344: #0: (ptrval) (rcu_read_lock){....}, at: sock_def_readable+0x0/0x710 include/linux/compiler.h:188 #1: (ptrval) (&cpuctx_lock){-...}, at: perf_ctx_lock kernel/events/core.c:155 [inline] #1: (ptrval) (&cpuctx_lock){-...}, at: event_function_local.constprop.113+0x282/0x5c0 kernel/events/core.c:318 #2: (ptrval) (&ctx->lock){-...}, at: perf_ctx_lock kernel/events/core.c:157 [inline] #2: (ptrval) (&ctx->lock){-...}, at: event_function_local.constprop.113+0x2a3/0x5c0 kernel/events/core.c:318 stack backtrace: CPU: 0 PID: 5344 Comm: syz-executor5 Not tainted 4.17.0-rc3+ #5 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 __warn.cold.8+0x73/0x1b3 kernel/panic.c:518 report_bug+0x252/0x2d0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] do_error_trap+0x1de/0x490 arch/x86/kernel/traps.c:296 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992 RIP: 0010:event_function_local.constprop.113+0x520/0x5c0 kernel/events/core.c:331 RSP: 0018:ffff8801dae07cf8 EFLAGS: 00010006 RAX: ffff8801c335a600 RBX: ffff8801b7025d00 RCX: ffffffff818fdefa RDX: 0000000000010000 RSI: ffffffff818fe0f0 RDI: 0000000000000005 RBP: ffff8801dae07d98 R08: ffff8801c335a600 R09: ffffed0036e04ba1 R10: ffffed0036e04ba1 R11: ffff8801b7025d0b R12: 1ffff1003b5c0fa2 R13: ffff8801dae31408 R14: ffff8801c893e5c0 R15: ffff8801b917a2c0 perf_event_disable_local kernel/events/core.c:2180 [inline] perf_pending_event+0x242/0x2a0 kernel/events/core.c:5809 irq_work_run_list+0x1b4/0x270 kernel/irq_work.c:155 irq_work_run+0x1d/0x50 kernel/irq_work.c:170 smp_irq_work_interrupt+0x10a/0x650 arch/x86/kernel/irq_work.c:21 irq_work_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:783 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa1/0xc0 kernel/locking/spinlock.c:184 RSP: 0018:ffff880197e6f618 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff09 RAX: dffffc0000000000 RBX: 0000000000000286 RCX: 0000000000000000 RDX: 1ffffffff11a316d RSI: ffff8801c335ae38 RDI: 0000000000000286 RBP: ffff880197e6f628 R08: ffff8801c335ae38 R09: 0000000000000006 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d8c57300 R13: 0000000000000001 R14: ffff880197e6f718 R15: 0000000000000286 spin_unlock_irqrestore include/linux/spinlock.h:365 [inline] __wake_up_common_lock+0x1c2/0x300 kernel/sched/wait.c:120 __wake_up_sync_key+0x19/0x20 kernel/sched/wait.c:197 sock_def_readable+0x249/0x710 net/core/sock.c:2705 unix_stream_sendmsg+0x5ef/0xd20 net/unix/af_unix.c:1901 ? unix_stream_sendpag Lost 33 message(s)! Shutting down cpus with NMI Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..