====================================================== WARNING: possible circular locking dependency detected 4.14.111 #1 Not tainted ------------------------------------------------------ syz-executor.5/24763 is trying to acquire lock: (&event->child_mutex){+.+.}, at: [] perf_event_for_each_child+0x8a/0x160 kernel/events/core.c:4682 but task is already holding lock: (&cpuctx_mutex){+.+.}, at: [] perf_event_ctx_lock_nested+0x150/0x2c0 kernel/events/core.c:1235 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&cpuctx_mutex){+.+.}: lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3994 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 perf_event_init_cpu+0xc2/0x170 kernel/events/core.c:11221 perf_event_init+0x2d8/0x31a kernel/events/core.c:11268 start_kernel+0x3b9/0x700 init/main.c:621 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:380 x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:361 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 -> #4 (pmus_lock){+.+.}: lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3994 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 perf_event_init_cpu+0x2f/0x170 kernel/events/core.c:11215 cpuhp_invoke_callback+0x1ec/0x1ac0 kernel/cpu.c:184 cpuhp_up_callbacks kernel/cpu.c:572 [inline] _cpu_up+0x228/0x530 kernel/cpu.c:1134 do_cpu_up+0x121/0x150 kernel/cpu.c:1169 cpu_up+0x1b/0x20 kernel/cpu.c:1177 smp_init+0x157/0x173 kernel/smp.c:578 kernel_init_freeable+0x30e/0x538 init/main.c:1067 kernel_init+0x12/0x162 init/main.c:999 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 -> #3 (cpu_hotplug_lock.rw_sem){++++}: lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3994 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+0x3d/0xc0 kernel/cpu.c:295 static_key_slow_inc+0x13/0x30 kernel/jump_label.c:123 tracepoint_add_func kernel/tracepoint.c:223 [inline] tracepoint_probe_register_prio+0x4dc/0x6d0 kernel/tracepoint.c:283 tracepoint_probe_register+0x2b/0x40 kernel/tracepoint.c:304 trace_event_reg+0x277/0x330 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+0x450/0xaa0 kernel/trace/trace_event_perf.c:221 perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:8104 perf_try_init_event+0x170/0x210 kernel/events/core.c:9340 perf_init_event kernel/events/core.c:9378 [inline] perf_event_alloc.part.0+0xd48/0x2540 kernel/events/core.c:9638 perf_event_alloc kernel/events/core.c:9991 [inline] SYSC_perf_event_open+0xa2d/0x24c0 kernel/events/core.c:10095 SyS_perf_event_open+0x34/0x40 kernel/events/core.c:9981 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #2 (tracepoints_mutex){+.+.}: lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3994 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 tracepoint_probe_register_prio+0x36/0x6d0 kernel/tracepoint.c:279 tracepoint_probe_register+0x2b/0x40 kernel/tracepoint.c:304 trace_event_reg+0x277/0x330 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+0x450/0xaa0 kernel/trace/trace_event_perf.c:221 perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:8104 perf_try_init_event+0x170/0x210 kernel/events/core.c:9340 perf_init_event kernel/events/core.c:9378 [inline] perf_event_alloc.part.0+0xd48/0x2540 kernel/events/core.c:9638 perf_event_alloc kernel/events/core.c:9991 [inline] SYSC_perf_event_open+0xa2d/0x24c0 kernel/events/core.c:10095 SyS_perf_event_open+0x34/0x40 kernel/events/core.c:9981 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #1 (event_mutex){+.+.}: lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3994 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xe8/0x1470 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+0x16/0x20 kernel/events/core.c:8088 _free_event+0x332/0xe70 kernel/events/core.c:4238 free_event+0x38/0x50 kernel/events/core.c:4265 perf_event_release_kernel+0x364/0x7a0 kernel/events/core.c:4409 perf_release+0x37/0x50 kernel/events/core.c:4435 __fput+0x277/0x7a0 fs/file_table.c:210 ____fput+0x16/0x20 fs/file_table.c:244 task_work_run+0x119/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1da/0x220 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:267 [inline] do_syscall_64+0x4a9/0x630 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #0 (&event->child_mutex){+.+.}: check_prev_add kernel/locking/lockdep.c:1901 [inline] check_prevs_add kernel/locking/lockdep.c:2018 [inline] validate_chain kernel/locking/lockdep.c:2460 [inline] __lock_acquire+0x2c89/0x45e0 kernel/locking/lockdep.c:3487 lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3994 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 perf_event_for_each_child+0x8a/0x160 kernel/events/core.c:4682 _perf_ioctl kernel/events/core.c:4866 [inline] perf_ioctl+0x1df/0xcb0 kernel/events/core.c:4878 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x7b9/0x1070 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 other info that might help us debug this: Chain exists of: &event->child_mutex --> pmus_lock --> &cpuctx_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&cpuctx_mutex); lock(pmus_lock); lock(&cpuctx_mutex); lock(&event->child_mutex); *** DEADLOCK *** 1 lock held by syz-executor.5/24763: #0: (&cpuctx_mutex){+.+.}, at: [] perf_event_ctx_lock_nested+0x150/0x2c0 kernel/events/core.c:1235 stack backtrace: CPU: 0 PID: 24763 Comm: syz-executor.5 Not tainted 4.14.111 #1 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+0x138/0x19c lib/dump_stack.c:53 print_circular_bug.isra.0.cold+0x1cc/0x28f kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1901 [inline] check_prevs_add kernel/locking/lockdep.c:2018 [inline] validate_chain kernel/locking/lockdep.c:2460 [inline] __lock_acquire+0x2c89/0x45e0 kernel/locking/lockdep.c:3487 lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3994 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xe8/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 perf_event_for_each_child+0x8a/0x160 kernel/events/core.c:4682 _perf_ioctl kernel/events/core.c:4866 [inline] perf_ioctl+0x1df/0xcb0 kernel/events/core.c:4878 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x7b9/0x1070 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x458c29 RSP: 002b:00007f7efe66ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458c29 RDX: 0000000000000000 RSI: 0000000000002403 RDI: 0000000000000004 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7efe66b6d4 R13: 00000000004c2179 R14: 00000000004d4ac0 R15: 00000000ffffffff kobject: 'loop4' (ffff8880a4ac0120): kobject_uevent_env kobject: 'loop4' (ffff8880a4ac0120): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop2' (ffff8880a4a106a0): kobject_uevent_env kobject: 'loop2' (ffff8880a4a106a0): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop0' (ffff8880a4952560): kobject_uevent_env kobject: 'loop0' (ffff8880a4952560): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop3' (ffff8880a4a560a0): kobject_uevent_env kobject: 'loop3' (ffff8880a4a560a0): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop5' (ffff8880a4b0ca20): kobject_uevent_env kobject: 'loop5' (ffff8880a4b0ca20): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop5' (ffff8880a4b0ca20): kobject_uevent_env kobject: 'loop5' (ffff8880a4b0ca20): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop0' (ffff8880a4952560): kobject_uevent_env kobject: 'loop0' (ffff8880a4952560): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop5' (ffff8880a4b0ca20): kobject_uevent_env kobject: 'loop5' (ffff8880a4b0ca20): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop1' (ffff8880a49c9760): kobject_uevent_env kobject: 'loop1' (ffff8880a49c9760): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop5' (ffff8880a4b0ca20): kobject_uevent_env kobject: 'loop5' (ffff8880a4b0ca20): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop3' (ffff8880a4a560a0): kobject_uevent_env kobject: 'loop3' (ffff8880a4a560a0): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop2' (ffff8880a4a106a0): kobject_uevent_env kobject: 'loop2' (ffff8880a4a106a0): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop4' (ffff8880a4ac0120): kobject_uevent_env kobject: 'loop4' (ffff8880a4ac0120): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop5' (ffff8880a4b0ca20): kobject_uevent_env kobject: 'loop5' (ffff8880a4b0ca20): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop2' (ffff8880a4a106a0): kobject_uevent_env kobject: 'loop2' (ffff8880a4a106a0): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop5' (ffff8880a4b0ca20): kobject_uevent_env kobject: 'loop5' (ffff8880a4b0ca20): fill_kobj_path: path = '/devices/virtual/block/loop5' netlink: 8 bytes leftover after parsing attributes in process `syz-executor.3'. kobject: 'loop0' (ffff8880a4952560): kobject_uevent_env kobject: 'loop0' (ffff8880a4952560): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'rx-0' (ffff88808ee906d0): kobject_cleanup, parent ffff88808eb3ae48 kobject: 'loop2' (ffff8880a4a106a0): kobject_uevent_env kobject: 'rx-0' (ffff88808ee906d0): auto cleanup 'remove' event kobject: 'loop2' (ffff8880a4a106a0): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'rx-0' (ffff88808ee906d0): kobject_uevent_env kobject: 'loop5' (ffff8880a4b0ca20): kobject_uevent_env kobject: 'loop5' (ffff8880a4b0ca20): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop2' (ffff8880a4a106a0): kobject_uevent_env kobject: 'rx-0' (ffff88808ee906d0): fill_kobj_path: path = '/devices/virtual/net/nlmon0/queues/rx-0' kobject: 'loop2' (ffff8880a4a106a0): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'rx-0' (ffff88808ee906d0): auto cleanup kobject_del kobject: 'loop4' (ffff8880a4ac0120): kobject_uevent_env kobject: 'rx-0' (ffff88808ee906d0): calling ktype release kobject: 'loop4' (ffff8880a4ac0120): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'rx-0': free name kobject: 'tx-0' (ffff8880909bd318): kobject_cleanup, parent ffff88808eb3ae48 kobject: 'loop1' (ffff8880a49c9760): kobject_uevent_env kobject: 'loop1' (ffff8880a49c9760): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'tx-0' (ffff8880909bd318): auto cleanup 'remove' event kobject: 'loop0' (ffff8880a4952560): kobject_uevent_env kobject: 'tx-0' (ffff8880909bd318): kobject_uevent_env kobject: 'loop0' (ffff8880a4952560): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'tx-0' (ffff8880909bd318): fill_kobj_path: path = '/devices/virtual/net/nlmon0/queues/tx-0' kobject: 'loop5' (ffff8880a4b0ca20): kobject_uevent_env kobject: 'tx-0' (ffff8880909bd318): auto cleanup kobject_del kobject: 'tx-0' (ffff8880909bd318): calling ktype release kobject: 'loop5' (ffff8880a4b0ca20): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'tx-0': free name kobject: 'queues' (ffff88808eb3ae48): kobject_cleanup, parent (null) kobject: 'queues' (ffff88808eb3ae48): calling ktype release kobject: 'queues' (ffff88808eb3ae48): kset_release kobject: 'loop2' (ffff8880a4a106a0): kobject_uevent_env kobject: 'queues': free name kobject: 'nlmon0' (ffff88806d128830): kobject_uevent_env kobject: 'nlmon0' (ffff88806d128830): fill_kobj_path: path = '/devices/virtual/net/nlmon0' kobject: 'loop2' (ffff8880a4a106a0): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop1' (ffff8880a49c9760): kobject_uevent_env kobject: 'loop1' (ffff8880a49c9760): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop1' (ffff8880a49c9760): kobject_uevent_env kobject: 'loop1' (ffff8880a49c9760): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'nlmon0' (ffff88806d128830): kobject_cleanup, parent (null) kobject: 'loop4' (ffff8880a4ac0120): kobject_uevent_env kobject: 'nlmon0' (ffff88806d128830): calling ktype release kobject: 'loop4' (ffff8880a4ac0120): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'nlmon0': free name kobject: 'loop1' (ffff8880a49c9760): kobject_uevent_env kobject: 'loop1' (ffff8880a49c9760): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop1' (ffff8880a49c9760): kobject_uevent_env kobject: 'loop1' (ffff8880a49c9760): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop0' (ffff8880a4952560): kobject_uevent_env kobject: 'loop0' (ffff8880a4952560): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop4' (ffff8880a4ac0120): kobject_uevent_env kobject: 'loop4' (ffff8880a4ac0120): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop3' (ffff8880a4a560a0): kobject_uevent_env netlink: 8 bytes leftover after parsing attributes in process `syz-executor.3'. kobject: 'loop3' (ffff8880a4a560a0): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop5' (ffff8880a4b0ca20): kobject_uevent_env kobject: 'loop5' (ffff8880a4b0ca20): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop0' (ffff8880a4952560): kobject_uevent_env kobject: 'loop0' (ffff8880a4952560): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop2' (ffff8880a4a106a0): kobject_uevent_env kobject: 'loop2' (ffff8880a4a106a0): fill_kobj_path: path = '/devices/virtual/block/loop2' netlink: 8 bytes leftover after parsing attributes in process `syz-executor.3'. kobject: 'loop3' (ffff8880a4a560a0): kobject_uevent_env kobject: 'loop3' (ffff8880a4a560a0): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop5' (ffff8880a4b0ca20): kobject_uevent_env kobject: 'loop5' (ffff8880a4b0ca20): fill_kobj_path: path = '/devices/virtual/block/loop5' netlink: 8 bytes leftover after parsing attributes in process `syz-executor.3'. kobject: 'loop0' (ffff8880a4952560): kobject_uevent_env kobject: 'loop0' (ffff8880a4952560): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop4' (ffff8880a4ac0120): kobject_uevent_env kobject: 'loop4' (ffff8880a4ac0120): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop1' (ffff8880a49c9760): kobject_uevent_env kobject: 'loop1' (ffff8880a49c9760): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop3' (ffff8880a4a560a0): kobject_uevent_env kobject: 'loop3' (ffff8880a4a560a0): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop1' (ffff8880a49c9760): kobject_uevent_env kobject: 'loop1' (ffff8880a49c9760): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop3' (ffff8880a4a560a0): kobject_uevent_env kobject: 'loop3' (ffff8880a4a560a0): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop1' (ffff8880a49c9760): kobject_uevent_env kobject: 'loop1' (ffff8880a49c9760): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop4' (ffff8880a4ac0120): kobject_uevent_env kobject: 'loop4' (ffff8880a4ac0120): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop2' (ffff8880a4a106a0): kobject_uevent_env kobject: 'loop2' (ffff8880a4a106a0): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop1' (ffff8880a49c9760): kobject_uevent_env kobject: 'loop1' (ffff8880a49c9760): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop3' (ffff8880a4a560a0): kobject_uevent_env kobject: 'loop3' (ffff8880a4a560a0): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop4' (ffff8880a4ac0120): kobject_uevent_env kobject: 'loop4' (ffff8880a4ac0120): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop1' (ffff8880a49c9760): kobject_uevent_env kobject: 'loop1' (ffff8880a49c9760): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop5' (ffff8880a4b0ca20): kobject_uevent_env kobject: 'loop5' (ffff8880a4b0ca20): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'loop0' (ffff8880a4952560): kobject_uevent_env kobject: 'loop0' (ffff8880a4952560): fill_kobj_path: path = '/devices/virtual/block/loop0' kobject: 'loop4' (ffff8880a4ac0120): kobject_uevent_env kobject: 'loop4' (ffff8880a4ac0120): fill_kobj_path: path = '/devices/virtual/block/loop4' kobject: 'loop1' (ffff8880a49c9760): kobject_uevent_env kobject: 'loop1' (ffff8880a49c9760): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop3' (ffff8880a4a560a0): kobject_uevent_env kobject: 'loop3' (ffff8880a4a560a0): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop1' (ffff8880a49c9760): kobject_uevent_env kobject: 'loop1' (ffff8880a49c9760): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'loop3' (ffff8880a4a560a0): kobject_uevent_env kobject: 'loop3' (ffff8880a4a560a0): fill_kobj_path: path = '/devices/virtual/block/loop3'