====================================================== WARNING: possible circular locking dependency detected 4.14.225-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/15591 is trying to acquire lock: (&event->child_mutex){+.+.}, at: [] perf_event_read_value+0x78/0x410 kernel/events/core.c:4453 but task is already holding lock: (&cpuctx_mutex){+.+.}, 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){+.+.}: __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:11250 perf_event_init+0x2cc/0x308 kernel/events/core.c:11297 start_kernel+0x46a/0x770 init/main.c:620 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 -> #4 (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:11244 cpuhp_invoke_callback+0x1e6/0x1a80 kernel/cpu.c:184 cpuhp_up_callbacks kernel/cpu.c:572 [inline] _cpu_up+0x219/0x500 kernel/cpu.c:1144 do_cpu_up+0x9a/0x160 kernel/cpu.c:1179 smp_init+0x197/0x1ac kernel/smp.c:578 kernel_init_freeable+0x3f4/0x614 init/main.c:1068 kernel_init+0xd/0x160 init/main.c:1000 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 -> #3 (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:295 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:8138 perf_try_init_event+0x15b/0x1f0 kernel/events/core.c:9369 perf_init_event kernel/events/core.c:9407 [inline] perf_event_alloc.part.0+0xe2d/0x2640 kernel/events/core.c:9667 perf_event_alloc kernel/events/core.c:10020 [inline] SYSC_perf_event_open kernel/events/core.c:10124 [inline] SyS_perf_event_open+0x67f/0x24b0 kernel/events/core.c:10010 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #2 (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:8138 perf_try_init_event+0x15b/0x1f0 kernel/events/core.c:9369 perf_init_event kernel/events/core.c:9407 [inline] perf_event_alloc.part.0+0xe2d/0x2640 kernel/events/core.c:9667 perf_event_alloc kernel/events/core.c:10020 [inline] SYSC_perf_event_open kernel/events/core.c:10124 [inline] SyS_perf_event_open+0x67f/0x24b0 kernel/events/core.c:10010 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #1 (event_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 perf_trace_destroy+0x23/0xf0 kernel/trace/trace_event_perf.c:234 _free_event+0x321/0xe20 kernel/events/core.c:4244 free_event+0x32/0x40 kernel/events/core.c:4271 perf_event_release_kernel+0x368/0x8a0 kernel/events/core.c:4415 perf_release+0x33/0x40 kernel/events/core.c:4441 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #0 (&event->child_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_event_read_value+0x78/0x410 kernel/events/core.c:4453 perf_read_one kernel/events/core.c:4575 [inline] __perf_read kernel/events/core.c:4626 [inline] perf_read+0x3e2/0x7c0 kernel/events/core.c:4639 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3eb/0x5b0 fs/read_write.c:919 vfs_readv+0xc8/0x120 fs/read_write.c:981 do_readv+0xfc/0x2c0 fs/read_write.c:1014 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->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.1/15591: #0: (&cpuctx_mutex){+.+.}, at: [] perf_event_ctx_lock_nested+0x14d/0x2c0 kernel/events/core.c:1241 stack backtrace: CPU: 0 PID: 15591 Comm: syz-executor.1 Not tainted 4.14.225-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_event_read_value+0x78/0x410 kernel/events/core.c:4453 perf_read_one kernel/events/core.c:4575 [inline] __perf_read kernel/events/core.c:4626 [inline] perf_read+0x3e2/0x7c0 kernel/events/core.c:4639 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3eb/0x5b0 fs/read_write.c:919 vfs_readv+0xc8/0x120 fs/read_write.c:981 do_readv+0xfc/0x2c0 fs/read_write.c:1014 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x465f69 RSP: 002b:00007f08dbe89188 EFLAGS: 00000246 ORIG_RAX: 0000000000000013 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465f69 RDX: 0000000000000001 RSI: 00000000200002c0 RDI: 0000000000000005 RBP: 00000000004bfa8f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007fffa624f6ff R14: 00007f08dbe89300 R15: 0000000000022000 print_req_error: I/O error, dev loop0, sector 0 PM: Marking nosave pages: [mem 0x00000000-0x00000fff] PM: Marking nosave pages: [mem 0x0009f000-0x000fffff] PM: Marking nosave pages: [mem 0xbfffd000-0xffffffff] PM: Basic memory bitmaps created PM: Basic memory bitmaps freed PM: Marking nosave pages: [mem 0x00000000-0x00000fff] PM: Marking nosave pages: [mem 0x0009f000-0x000fffff] PM: Marking nosave pages: [mem 0xbfffd000-0xffffffff] PM: Basic memory bitmaps created PM: Basic memory bitmaps freed kauditd_printk_skb: 13 callbacks suppressed audit: type=1804 audit(1615586043.221:13183): pid=15989 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir388044314/syzkaller.rngpZY/255/file0" dev="sda1" ino=15777 res=1 audit: type=1804 audit(1615586043.271:13184): pid=15989 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir388044314/syzkaller.rngpZY/255/file0" dev="sda1" ino=15777 res=1 audit: type=1804 audit(1615586043.911:13185): pid=16021 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.1" name="/root/syzkaller-testdir249971211/syzkaller.xcWm24/249/file0" dev="sda1" ino=16560 res=1 audit: type=1804 audit(1615586044.011:13186): pid=16033 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.1" name="/root/syzkaller-testdir249971211/syzkaller.xcWm24/250/file0" dev="sda1" ino=16002 res=1 audit: type=1804 audit(1615586044.711:13187): pid=16066 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.1" name="/root/syzkaller-testdir249971211/syzkaller.xcWm24/251/file0" dev="sda1" ino=16561 res=1 audit: type=1804 audit(1615586044.821:13188): pid=16083 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.1" name="/root/syzkaller-testdir249971211/syzkaller.xcWm24/252/file0" dev="sda1" ino=15953 res=1 audit: type=1804 audit(1615586044.911:13189): pid=16092 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.1" name="/root/syzkaller-testdir249971211/syzkaller.xcWm24/253/file0" dev="sda1" ino=16560 res=1 audit: type=1804 audit(1615586044.981:13190): pid=16100 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.1" name="/root/syzkaller-testdir249971211/syzkaller.xcWm24/254/file0" dev="sda1" ino=16002 res=1 netlink: 12 bytes leftover after parsing attributes in process `syz-executor.3'. audit: type=1804 audit(1615586045.541:13191): pid=16114 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.1" name="/root/syzkaller-testdir249971211/syzkaller.xcWm24/255/file0" dev="sda1" ino=16568 res=1 netlink: 12 bytes leftover after parsing attributes in process `syz-executor.3'. audit: type=1804 audit(1615586045.661:13192): pid=16125 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.1" name="/root/syzkaller-testdir249971211/syzkaller.xcWm24/256/file0" dev="sda1" ino=16565 res=1