====================================================== WARNING: possible circular locking dependency detected 4.15.0-rc8+ #7 Not tainted ------------------------------------------------------ syz-executor1/21423 is trying to acquire lock: (event_mutex){+.+.}, at: [<000000005e5e9b32>] perf_trace_destroy+0x28/0x100 kernel/trace/trace_event_perf.c:234 but task is already holding lock: (&event->child_mutex){+.+.}, at: [<00000000248e780c>] perf_event_release_kernel+0x2ea/0xc10 kernel/events/core.c:4260 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&event->child_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 perf_event_for_each_child+0x8a/0x150 kernel/events/core.c:4557 _perf_ioctl kernel/events/core.c:4736 [inline] perf_ioctl+0x35a/0x1430 kernel/events/core.c:4748 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x273/0x920 arch/x86/entry/common.c:285 return_from_SYSCALL_64+0x0/0x75 -> #4 (&cpuctx_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 perf_event_init_cpu+0xb6/0x160 kernel/events/core.c:11076 perf_event_init+0x4e9/0x549 kernel/events/core.c:11123 start_kernel+0x4cc/0x819 init/main.c:627 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378 x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:237 -> #3 (pmus_lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 perf_event_init_cpu+0x2f/0x160 kernel/events/core.c:11070 cpuhp_invoke_callback+0x2ea/0x1d20 kernel/cpu.c:182 cpuhp_up_callbacks kernel/cpu.c:477 [inline] _cpu_up+0x216/0x510 kernel/cpu.c:1036 do_cpu_up+0x73/0xa0 kernel/cpu.c:1066 cpu_up+0x18/0x20 kernel/cpu.c:1074 smp_init+0x13a/0x152 kernel/smp.c:578 kernel_init_freeable+0x2fe/0x521 init/main.c:1067 kernel_init+0x13/0x180 init/main.c:999 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:541 -> #2 (cpu_hotplug_lock.rw_sem){++++}: percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] cpus_read_lock+0x42/0x90 kernel/cpu.c:293 static_key_slow_inc+0x9d/0x3c0 kernel/jump_label.c:123 tracepoint_add_func kernel/tracepoint.c:223 [inline] tracepoint_probe_register_prio+0x80d/0x9a0 kernel/tracepoint.c:283 tracepoint_probe_register+0x2a/0x40 kernel/tracepoint.c:304 trace_event_reg+0x167/0x320 kernel/trace/trace_events.c:305 perf_trace_event_reg kernel/trace/trace_event_perf.c:122 [inline] perf_trace_event_init kernel/trace/trace_event_perf.c:197 [inline] perf_trace_init+0x4ef/0xab0 kernel/trace/trace_event_perf.c:221 perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:7959 perf_try_init_event+0xc9/0x1f0 kernel/events/core.c:9192 perf_init_event kernel/events/core.c:9230 [inline] perf_event_alloc+0x1cc6/0x2b00 kernel/events/core.c:9494 SYSC_perf_event_open+0x84e/0x2e00 kernel/events/core.c:9949 SyS_perf_event_open+0x39/0x50 kernel/events/core.c:9835 entry_SYSCALL_64_fastpath+0x29/0xa0 -> #1 (tracepoints_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 tracepoint_probe_register_prio+0xa0/0x9a0 kernel/tracepoint.c:279 tracepoint_probe_register+0x2a/0x40 kernel/tracepoint.c:304 trace_event_reg+0x167/0x320 kernel/trace/trace_events.c:305 perf_trace_event_reg kernel/trace/trace_event_perf.c:122 [inline] perf_trace_event_init kernel/trace/trace_event_perf.c:197 [inline] perf_trace_init+0x4ef/0xab0 kernel/trace/trace_event_perf.c:221 perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:7959 perf_try_init_event+0xc9/0x1f0 kernel/events/core.c:9192 perf_init_event kernel/events/core.c:9230 [inline] perf_event_alloc+0x1cc6/0x2b00 kernel/events/core.c:9494 SYSC_perf_event_open+0x84e/0x2e00 kernel/events/core.c:9949 SyS_perf_event_open+0x39/0x50 kernel/events/core.c:9835 entry_SYSCALL_64_fastpath+0x29/0xa0 -> #0 (event_mutex){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3914 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 perf_trace_destroy+0x28/0x100 kernel/trace/trace_event_perf.c:234 tp_perf_event_destroy+0x15/0x20 kernel/events/core.c:7943 _free_event+0x3bd/0x10f0 kernel/events/core.c:4104 free_event+0x84/0x150 kernel/events/core.c:4128 perf_event_release_kernel+0x54e/0xc10 kernel/events/core.c:4272 perf_release+0x37/0x50 kernel/events/core.c:4298 __fput+0x327/0x7e0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x199/0x270 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x9bb/0x1ad0 kernel/exit.c:865 do_group_exit+0x149/0x400 kernel/exit.c:968 get_signal+0x73f/0x16c0 kernel/signal.c:2335 do_signal+0x90/0x1eb0 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264 entry_SYSCALL_64_fastpath+0x9e/0xa0 other info that might help us debug this: Chain exists of: event_mutex --> &cpuctx_mutex --> &event->child_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&event->child_mutex); lock(&cpuctx_mutex); lock(&event->child_mutex); lock(event_mutex); *** DEADLOCK *** 2 locks held by syz-executor1/21423: #0: (&ctx->mutex){+.+.}, at: [<00000000037301f7>] perf_event_release_kernel+0x2dc/0xc10 kernel/events/core.c:4259 #1: (&event->child_mutex){+.+.}, at: [<00000000248e780c>] perf_event_release_kernel+0x2ea/0xc10 kernel/events/core.c:4260 stack backtrace: CPU: 0 PID: 21423 Comm: syz-executor1 Not tainted 4.15.0-rc8+ #7 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_circular_bug.isra.37+0x2cd/0x2dc kernel/locking/lockdep.c:1218 check_prev_add kernel/locking/lockdep.c:1858 [inline] check_prevs_add kernel/locking/lockdep.c:1971 [inline] validate_chain kernel/locking/lockdep.c:2412 [inline] __lock_acquire+0x30a8/0x3e00 kernel/locking/lockdep.c:3426 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3914 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 perf_trace_destroy+0x28/0x100 kernel/trace/trace_event_perf.c:234 tp_perf_event_destroy+0x15/0x20 kernel/events/core.c:7943 _free_event+0x3bd/0x10f0 kernel/events/core.c:4104 free_event+0x84/0x150 kernel/events/core.c:4128 perf_event_release_kernel+0x54e/0xc10 kernel/events/core.c:4272 perf_release+0x37/0x50 kernel/events/core.c:4298 __fput+0x327/0x7e0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x199/0x270 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x9bb/0x1ad0 kernel/exit.c:865 do_group_exit+0x149/0x400 kernel/exit.c:968 get_signal+0x73f/0x16c0 kernel/signal.c:2335 do_signal+0x90/0x1eb0 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264 entry_SYSCALL_64_fastpath+0x9e/0xa0 RIP: 0033:0x452f19 RSP: 002b:00007fec26a79ce8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000071bf80 RCX: 0000000000452f19 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000071bf80 RBP: 000000000071bf80 R08: 0000000000000431 R09: 000000000071bf58 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffee1b5690f R14: 00007fec26a7a9c0 R15: 0000000000000002 cgroup: cgroup2: unknown option "" cgroup: cgroup2: unknown option "" 9pnet_virtio: no channels available for device ./file0 9pnet_virtio: no channels available for device ./file0 xprt_adjust_timeout: rq_timeout = 0! xprt_adjust_timeout: rq_timeout = 0! FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 22306 Comm: syz-executor4 Not tainted 4.15.0-rc8+ #7 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 fail_dump lib/fault-inject.c:51 [inline] should_fail+0x8c0/0xa40 lib/fault-inject.c:149 should_failslab+0xec/0x120 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:421 [inline] slab_alloc_node mm/slab.c:3289 [inline] kmem_cache_alloc_node+0x56/0x760 mm/slab.c:3632 __alloc_skb+0xf1/0x780 net/core/skbuff.c:193 alloc_skb_fclone include/linux/skbuff.h:1025 [inline] tipc_buf_acquire+0x2d/0xf0 net/tipc/msg.c:66 tipc_msg_create+0x36/0x280 net/tipc/msg.c:98 __tipc_shutdown+0x84f/0xc80 net/tipc/socket.c:532 tipc_release+0x110/0xff0 net/tipc/socket.c:574 sock_release+0x8d/0x1e0 net/socket.c:595 sock_close+0x16/0x20 net/socket.c:1123 __fput+0x327/0x7e0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x199/0x270 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x296/0x310 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264 entry_SYSCALL_64_fastpath+0x9e/0xa0 RIP: 0033:0x452f19 RSP: 002b:00007f4c77a3cc58 EFLAGS: 00000212 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 000000000071bea0 RCX: 0000000000452f19 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000014 RBP: 0000000000000052 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006ef850 R13: 0000000000000015 R14: 00007f4c77a3d6d4 R15: ffffffffffffffff cgroup: cgroup2: unknown option "·’Gˆ*þlZØMö¤6ƒ 4«š¡ÔÉ–Ò„8pbdÿnÑ"'Þ«pþ££QrßXÖ‹8šÊ ¼î'7p®2§lâ~KR0ÞÊ4äì~ì¾ç¢”" cgroup: cgroup2: unknown option "·’Gˆ*þlZØMö¤6ƒ 4«š¡ÔÉ–Ò„8pbdÿnÑ"'Þ«pþ££QrßXÖ‹8šÊ ¼î'7p®2§lâ~KR0ÞÊ4äì~ì¾ç¢”" NFS: bad mount option value specified: v4†å