====================================================== WARNING: possible circular locking dependency detected 4.15.0-rc2-mm1+ #39 Not tainted ------------------------------------------------------ syz-executor0/3387 is trying to acquire lock: (event_mutex){+.+.}, at: [<0000000079828d3d>] perf_trace_destroy+0x28/0x100 kernel/trace/trace_event_perf.c:234 but task is already holding lock: (&mm->mmap_sem){++++}, at: [<00000000c1fecfd0>] vm_mmap_pgoff+0x198/0x280 mm/util.c:331 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #7 (&mm->mmap_sem){++++}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 __might_fault+0x13a/0x1d0 mm/memory.c:4524 _copy_to_user+0x2c/0xc0 lib/usercopy.c:25 copy_to_user include/linux/uaccess.h:155 [inline] filldir+0x1a7/0x320 fs/readdir.c:196 dir_emit_dot include/linux/fs.h:3378 [inline] dir_emit_dots include/linux/fs.h:3389 [inline] dcache_readdir+0x12d/0x5e0 fs/libfs.c:192 iterate_dir+0x1ca/0x540 fs/readdir.c:51 SYSC_getdents fs/readdir.c:231 [inline] SyS_getdents+0x225/0x450 fs/readdir.c:212 entry_SYSCALL_64_fastpath+0x1f/0x96 -> #6 (&sb->s_type->i_mutex_key#5){++++}: context_switch kernel/sched/core.c:2803 [inline] __schedule+0x8f3/0x2060 kernel/sched/core.c:3376 schedule+0xf5/0x430 kernel/sched/core.c:3435 devtmpfsd+0x420/0x4b0 drivers/base/devtmpfs.c:408 kthread+0x37a/0x440 kernel/kthread.c:238 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:524 -> #5 ((completion)&req.done){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 complete_acquire include/linux/completion.h:40 [inline] __wait_for_common kernel/sched/completion.c:109 [inline] wait_for_common kernel/sched/completion.c:123 [inline] wait_for_completion+0xcb/0x7b0 kernel/sched/completion.c:144 devtmpfs_create_node+0x32b/0x4a0 drivers/base/devtmpfs.c:115 device_add+0x120f/0x1640 drivers/base/core.c:1824 device_create_groups_vargs+0x1f3/0x250 drivers/base/core.c:2430 device_create_vargs drivers/base/core.c:2470 [inline] device_create+0xda/0x110 drivers/base/core.c:2506 msr_device_create+0x26/0x40 arch/x86/kernel/msr.c:188 cpuhp_invoke_callback+0x2ea/0x1d20 kernel/cpu.c:182 cpuhp_thread_fun+0x48e/0x7e0 kernel/cpu.c:571 smpboot_thread_fn+0x450/0x7c0 kernel/smpboot.c:164 kthread+0x37a/0x440 kernel/kthread.c:238 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:524 -> #4 (cpuhp_state-up){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 cpuhp_lock_acquire kernel/cpu.c:85 [inline] cpuhp_invoke_ap_callback kernel/cpu.c:605 [inline] cpuhp_issue_call+0x1e5/0x520 kernel/cpu.c:1495 __cpuhp_setup_state_cpuslocked+0x282/0x600 kernel/cpu.c:1642 __cpuhp_setup_state+0xb0/0x140 kernel/cpu.c:1671 cpuhp_setup_state include/linux/cpuhotplug.h:201 [inline] page_writeback_init+0x4d/0x71 mm/page-writeback.c:2081 pagecache_init+0x48/0x4f mm/filemap.c:976 start_kernel+0x6c1/0x754 init/main.c:697 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 (cpuhp_state_mutex){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 __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 __cpuhp_setup_state_cpuslocked+0x5b/0x600 kernel/cpu.c:1617 __cpuhp_setup_state+0xb0/0x140 kernel/cpu.c:1671 cpuhp_setup_state_nocalls include/linux/cpuhotplug.h:229 [inline] kvm_guest_init+0x1f3/0x20f arch/x86/kernel/kvm.c:528 setup_arch+0x17e8/0x1a02 arch/x86/kernel/setup.c:1266 start_kernel+0xa5/0x754 init/main.c:532 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 -> #2 (cpu_hotplug_lock.rw_sem){++++}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 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:222 [inline] tracepoint_probe_register_prio+0x80d/0x9a0 kernel/tracepoint.c:282 tracepoint_probe_register+0x2a/0x40 kernel/tracepoint.c:303 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:7956 perf_try_init_event+0xc9/0x1f0 kernel/events/core.c:9182 perf_init_event kernel/events/core.c:9220 [inline] perf_event_alloc+0x1cc6/0x2b00 kernel/events/core.c:9484 SYSC_perf_event_open+0x84e/0x2e00 kernel/events/core.c:9939 SyS_perf_event_open+0x39/0x50 kernel/events/core.c:9825 entry_SYSCALL_64_fastpath+0x1f/0x96 -> #1 (tracepoints_mutex){+.+.}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 __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:278 tracepoint_probe_register+0x2a/0x40 kernel/tracepoint.c:303 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:7956 perf_try_init_event+0xc9/0x1f0 kernel/events/core.c:9182 perf_init_event kernel/events/core.c:9220 [inline] perf_event_alloc+0x1cc6/0x2b00 kernel/events/core.c:9484 SYSC_perf_event_open+0x84e/0x2e00 kernel/events/core.c:9939 SyS_perf_event_open+0x39/0x50 kernel/events/core.c:9825 entry_SYSCALL_64_fastpath+0x1f/0x96 -> #0 (event_mutex){+.+.}: check_prevs_add kernel/locking/lockdep.c:2031 [inline] validate_chain kernel/locking/lockdep.c:2473 [inline] __lock_acquire+0x3498/0x47f0 kernel/locking/lockdep.c:3500 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 __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:7940 _free_event+0x3bd/0x10f0 kernel/events/core.c:4104 put_event+0x24/0x30 kernel/events/core.c:4187 perf_mmap_close+0x60d/0x1010 kernel/events/core.c:5146 remove_vma+0xb4/0x1b0 mm/mmap.c:172 remove_vma_list mm/mmap.c:2490 [inline] do_munmap+0x82a/0xdf0 mm/mmap.c:2731 mmap_region+0x59e/0x15a0 mm/mmap.c:1646 do_mmap+0x6c6/0xe10 mm/mmap.c:1483 do_mmap_pgoff include/linux/mm.h:2217 [inline] vm_mmap_pgoff+0x1de/0x280 mm/util.c:333 SYSC_mmap_pgoff mm/mmap.c:1533 [inline] SyS_mmap_pgoff+0x23b/0x5f0 mm/mmap.c:1491 SYSC_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:91 entry_SYSCALL_64_fastpath+0x1f/0x96 other info that might help us debug this: Chain exists of: event_mutex --> &sb->s_type->i_mutex_key#5 --> &mm->mmap_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&mm->mmap_sem); lock(&sb->s_type->i_mutex_key#5); lock(&mm->mmap_sem); lock(event_mutex); *** DEADLOCK *** 1 lock held by syz-executor0/3387: #0: (&mm->mmap_sem){++++}, at: [<00000000c1fecfd0>] vm_mmap_pgoff+0x198/0x280 mm/util.c:331 stack backtrace: CPU: 0 PID: 3387 Comm: syz-executor0 Not tainted 4.15.0-rc2-mm1+ #39 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+0x42d/0x610 kernel/locking/lockdep.c:1271 check_prev_add+0x666/0x15f0 kernel/locking/lockdep.c:1914 check_prevs_add kernel/locking/lockdep.c:2031 [inline] validate_chain kernel/locking/lockdep.c:2473 [inline] __lock_acquire+0x3498/0x47f0 kernel/locking/lockdep.c:3500 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004 __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:7940 _free_event+0x3bd/0x10f0 kernel/events/core.c:4104 put_event+0x24/0x30 kernel/events/core.c:4187 perf_mmap_close+0x60d/0x1010 kernel/events/core.c:5146 remove_vma+0xb4/0x1b0 mm/mmap.c:172 remove_vma_list mm/mmap.c:2490 [inline] do_munmap+0x82a/0xdf0 mm/mmap.c:2731 mmap_region+0x59e/0x15a0 mm/mmap.c:1646 do_mmap+0x6c6/0xe10 mm/mmap.c:1483 do_mmap_pgoff include/linux/mm.h:2217 [inline] vm_mmap_pgoff+0x1de/0x280 mm/util.c:333 SYSC_mmap_pgoff mm/mmap.c:1533 [inline] SyS_mmap_pgoff+0x23b/0x5f0 mm/mmap.c:1491 SYSC_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:91 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x452a39 RSP: 002b:00007f30b6730c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f30b6731700 RCX: 0000000000452a39 RDX: 0000000000000003 RSI: 0000000000292000 RDI: 0000000020000000 RBP: 00007ffc308b8680 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000000032 R11: 0000000000000212 R12: 0000000000000000 R13: 00007ffc308b85ff R14: 00007f30b67319c0 R15: 0000000000000007