====================================================== WARNING: possible circular locking dependency detected 4.14.262-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/27500 is trying to acquire lock: (event_mutex){+.+.}, at: [] perf_trace_init+0x4f/0xa30 kernel/trace/trace_event_perf.c:216 but task is already holding lock: (&cpuctx_mutex/1){+.+.}, at: [] perf_event_ctx_lock_nested+0x14d/0x2c0 kernel/events/core.c:1241 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&cpuctx_mutex/1){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 mutex_lock_double kernel/events/core.c:9933 [inline] __perf_event_ctx_lock_double kernel/events/core.c:9992 [inline] SYSC_perf_event_open kernel/events/core.c:10254 [inline] SyS_perf_event_open+0xd28/0x24b0 kernel/events/core.c:10012 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #4 (&cpuctx_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 perf_event_init_cpu+0xb7/0x170 kernel/events/core.c:11252 perf_event_init+0x2cc/0x308 kernel/events/core.c:11299 start_kernel+0x46a/0x770 init/main.c:620 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 -> #3 (pmus_lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 perf_event_init_cpu+0x2c/0x170 kernel/events/core.c:11246 cpuhp_invoke_callback+0x1e6/0x1a80 kernel/cpu.c:185 cpuhp_up_callbacks kernel/cpu.c:573 [inline] _cpu_up+0x21e/0x520 kernel/cpu.c:1192 do_cpu_up+0x9a/0x160 kernel/cpu.c:1228 smp_init+0x197/0x1ac kernel/smp.c:578 kernel_init_freeable+0x406/0x626 init/main.c:1068 kernel_init+0xd/0x15e init/main.c:1000 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 -> #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+0x39/0xc0 kernel/cpu.c:296 static_key_slow_inc+0xe/0x20 kernel/jump_label.c:123 tracepoint_add_func+0x747/0xa40 kernel/tracepoint.c:269 tracepoint_probe_register_prio kernel/tracepoint.c:331 [inline] tracepoint_probe_register+0x8c/0xc0 kernel/tracepoint.c:352 trace_event_reg+0x272/0x330 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+0x424/0xa30 kernel/trace/trace_event_perf.c:221 perf_tp_event_init+0x79/0xf0 kernel/events/core.c:8140 perf_try_init_event+0x15b/0x1f0 kernel/events/core.c:9371 perf_init_event kernel/events/core.c:9409 [inline] perf_event_alloc.part.0+0xe2d/0x2640 kernel/events/core.c:9669 perf_event_alloc kernel/events/core.c:10022 [inline] SYSC_perf_event_open kernel/events/core.c:10126 [inline] SyS_perf_event_open+0x67f/0x24b0 kernel/events/core.c:10012 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #1 (tracepoints_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 tracepoint_probe_register_prio kernel/tracepoint.c:327 [inline] tracepoint_probe_register+0x68/0xc0 kernel/tracepoint.c:352 trace_event_reg+0x272/0x330 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+0x424/0xa30 kernel/trace/trace_event_perf.c:221 perf_tp_event_init+0x79/0xf0 kernel/events/core.c:8140 perf_try_init_event+0x15b/0x1f0 kernel/events/core.c:9371 perf_init_event kernel/events/core.c:9409 [inline] perf_event_alloc.part.0+0xe2d/0x2640 kernel/events/core.c:9669 perf_event_alloc kernel/events/core.c:10022 [inline] SYSC_perf_event_open kernel/events/core.c:10126 [inline] SyS_perf_event_open+0x67f/0x24b0 kernel/events/core.c:10012 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #0 (event_mutex){+.+.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 perf_trace_init+0x4f/0xa30 kernel/trace/trace_event_perf.c:216 perf_tp_event_init+0x79/0xf0 kernel/events/core.c:8140 perf_try_init_event+0xdf/0x1f0 kernel/events/core.c:9371 perf_init_event kernel/events/core.c:9409 [inline] perf_event_alloc.part.0+0xe2d/0x2640 kernel/events/core.c:9669 perf_event_alloc kernel/events/core.c:10022 [inline] SYSC_perf_event_open kernel/events/core.c:10126 [inline] SyS_perf_event_open+0x67f/0x24b0 kernel/events/core.c:10012 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb other info that might help us debug this: Chain exists of: event_mutex --> &cpuctx_mutex --> &cpuctx_mutex/1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&cpuctx_mutex/1); lock(&cpuctx_mutex); lock(&cpuctx_mutex/1); lock(event_mutex); *** DEADLOCK *** 2 locks held by syz-executor.4/27500: #0: (&pmus_srcu){....}, at: [] fdput include/linux/file.h:40 [inline] #0: (&pmus_srcu){....}, at: [] perf_cgroup_connect kernel/events/core.c:849 [inline] #0: (&pmus_srcu){....}, at: [] perf_event_alloc.part.0+0xc44/0x2640 kernel/events/core.c:9664 #1: (&cpuctx_mutex/1){+.+.}, at: [] perf_event_ctx_lock_nested+0x14d/0x2c0 kernel/events/core.c:1241 stack backtrace: CPU: 0 PID: 27500 Comm: syz-executor.4 Not tainted 4.14.262-syzkaller #0 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+0x1b2/0x281 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 perf_trace_init+0x4f/0xa30 kernel/trace/trace_event_perf.c:216 perf_tp_event_init+0x79/0xf0 kernel/events/core.c:8140 perf_try_init_event+0xdf/0x1f0 kernel/events/core.c:9371 perf_init_event kernel/events/core.c:9409 [inline] perf_event_alloc.part.0+0xe2d/0x2640 kernel/events/core.c:9669 perf_event_alloc kernel/events/core.c:10022 [inline] SYSC_perf_event_open kernel/events/core.c:10126 [inline] SyS_perf_event_open+0x67f/0x24b0 kernel/events/core.c:10012 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fcc66ecefe9 RSP: 002b:00007fcc65844168 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007fcc66fe1f60 RCX: 00007fcc66ecefe9 RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 00000000200000c0 RBP: 00007fcc66f2908d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdff97a46f R14: 00007fcc65844300 R15: 0000000000022000 netlink: 40 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 40 bytes leftover after parsing attributes in process `syz-executor.3'. netlink: 40 bytes leftover after parsing attributes in process `syz-executor.3'. caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'. unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1