====================================================== WARNING: possible circular locking dependency detected 5.3.0-rc4-next-20190814 #66 Not tainted ------------------------------------------------------ syz-executor.2/27609 is trying to acquire lock: ffffffff88f5eef0 (cpu_hotplug_lock.rw_sem){++++}, at: __static_key_slow_dec kernel/jump_label.c:254 [inline] ffffffff88f5eef0 (cpu_hotplug_lock.rw_sem){++++}, at: static_key_slow_dec+0x54/0xa0 kernel/jump_label.c:270 but task is already holding lock: ffff88805ff4f4d0 (&mm->mmap_sem#2){++++}, at: vm_mmap_pgoff+0x173/0x230 mm/util.c:494 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&mm->mmap_sem#2){++++}: down_write+0x93/0x150 kernel/locking/rwsem.c:1534 mpol_rebind_mm+0x25/0xd0 mm/mempolicy.c:382 cpuset_attach+0x226/0x420 kernel/cgroup/cpuset.c:2204 cgroup_migrate_execute+0xc56/0x1350 kernel/cgroup/cgroup.c:2524 cgroup_migrate+0x14f/0x1f0 kernel/cgroup/cgroup.c:2780 cgroup_attach_task+0x57f/0x860 kernel/cgroup/cgroup.c:2817 __cgroup1_procs_write.constprop.0+0x321/0x400 kernel/cgroup/cgroup-v1.c:522 cgroup1_procs_write+0x2b/0x40 kernel/cgroup/cgroup-v1.c:535 cgroup_file_write+0x241/0x790 kernel/cgroup/cgroup.c:3754 kernfs_fop_write+0x2b8/0x480 fs/kernfs/file.c:315 __vfs_write+0x8a/0x110 fs/read_write.c:494 vfs_write+0x268/0x5d0 fs/read_write.c:558 ksys_write+0x14f/0x290 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:620 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&cpuset_rwsem){++++}: percpu_down_read include/linux/percpu-rwsem.h:40 [inline] cpuset_read_lock+0x3e/0x150 kernel/cgroup/cpuset.c:340 __sched_setscheduler+0xca2/0x2110 kernel/sched/core.c:4718 _sched_setscheduler+0x10a/0x1b0 kernel/sched/core.c:4890 sched_setscheduler_nocheck+0xb/0x10 kernel/sched/core.c:4936 __kthread_create_on_node+0x32a/0x460 kernel/kthread.c:349 kthread_create_on_node+0xbb/0xf0 kernel/kthread.c:388 create_worker+0x25c/0x570 kernel/workqueue.c:1929 workqueue_prepare_cpu+0xa1/0x100 kernel/workqueue.c:4982 cpuhp_invoke_callback+0x21a/0x1c60 kernel/cpu.c:172 cpuhp_up_callbacks kernel/cpu.c:593 [inline] _cpu_up+0x289/0x550 kernel/cpu.c:1153 do_cpu_up+0x171/0x190 kernel/cpu.c:1188 cpu_up+0x1b/0x20 kernel/cpu.c:1196 smp_init+0x248/0x261 kernel/smp.c:593 kernel_init_freeable+0x339/0x5be init/main.c:1185 kernel_init+0x12/0x1c5 init/main.c:1110 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 -> #0 (cpu_hotplug_lock.rw_sem){++++}: check_prev_add kernel/locking/lockdep.c:2476 [inline] check_prevs_add kernel/locking/lockdep.c:2581 [inline] validate_chain kernel/locking/lockdep.c:2971 [inline] __lock_acquire+0x25b6/0x4e70 kernel/locking/lockdep.c:3955 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487 percpu_down_read include/linux/percpu-rwsem.h:40 [inline] cpus_read_lock+0x3e/0x150 kernel/cpu.c:292 __static_key_slow_dec kernel/jump_label.c:254 [inline] static_key_slow_dec+0x54/0xa0 kernel/jump_label.c:270 sw_perf_event_destroy+0x8b/0x130 kernel/events/core.c:8482 _free_event+0x354/0x13a0 kernel/events/core.c:4470 put_event+0x47/0x60 kernel/events/core.c:4564 perf_mmap_close+0x585/0xe00 kernel/events/core.c:5567 remove_vma+0xb2/0x180 mm/mmap.c:183 remove_vma_list mm/mmap.c:2615 [inline] __do_munmap+0x7b0/0x10f0 mm/mmap.c:2859 do_munmap mm/mmap.c:2867 [inline] mmap_region+0x227/0x1760 mm/mmap.c:1745 do_mmap+0x853/0x1180 mm/mmap.c:1575 do_mmap_pgoff include/linux/mm.h:2395 [inline] vm_mmap_pgoff+0x1c5/0x230 mm/util.c:496 ksys_mmap_pgoff+0x4aa/0x630 mm/mmap.c:1625 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline] __x64_sys_mmap+0xe9/0x1b0 arch/x86/kernel/sys_x86_64.c:91 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: cpu_hotplug_lock.rw_sem --> &cpuset_rwsem --> &mm->mmap_sem#2 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&mm->mmap_sem#2); lock(&cpuset_rwsem); lock(&mm->mmap_sem#2); lock(cpu_hotplug_lock.rw_sem); *** DEADLOCK *** 1 lock held by syz-executor.2/27609: #0: ffff88805ff4f4d0 (&mm->mmap_sem#2){++++}, at: vm_mmap_pgoff+0x173/0x230 mm/util.c:494 stack backtrace: CPU: 1 PID: 27609 Comm: syz-executor.2 Not tainted 5.3.0-rc4-next-20190814 #66 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_circular_bug.isra.0.cold+0x163/0x172 kernel/locking/lockdep.c:1685 check_noncircular+0x32e/0x3e0 kernel/locking/lockdep.c:1809 check_prev_add kernel/locking/lockdep.c:2476 [inline] check_prevs_add kernel/locking/lockdep.c:2581 [inline] validate_chain kernel/locking/lockdep.c:2971 [inline] __lock_acquire+0x25b6/0x4e70 kernel/locking/lockdep.c:3955 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4487 percpu_down_read include/linux/percpu-rwsem.h:40 [inline] cpus_read_lock+0x3e/0x150 kernel/cpu.c:292 __static_key_slow_dec kernel/jump_label.c:254 [inline] static_key_slow_dec+0x54/0xa0 kernel/jump_label.c:270 sw_perf_event_destroy+0x8b/0x130 kernel/events/core.c:8482 _free_event+0x354/0x13a0 kernel/events/core.c:4470 put_event+0x47/0x60 kernel/events/core.c:4564 perf_mmap_close+0x585/0xe00 kernel/events/core.c:5567 remove_vma+0xb2/0x180 mm/mmap.c:183 remove_vma_list mm/mmap.c:2615 [inline] __do_munmap+0x7b0/0x10f0 mm/mmap.c:2859 do_munmap mm/mmap.c:2867 [inline] mmap_region+0x227/0x1760 mm/mmap.c:1745 do_mmap+0x853/0x1180 mm/mmap.c:1575 do_mmap_pgoff include/linux/mm.h:2395 [inline] vm_mmap_pgoff+0x1c5/0x230 mm/util.c:496 ksys_mmap_pgoff+0x4aa/0x630 mm/mmap.c:1625 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline] __x64_sys_mmap+0xe9/0x1b0 arch/x86/kernel/sys_x86_64.c:91 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459829 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fdb3d655c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000459829 RDX: 0000000000000000 RSI: 0000000000003000 RDI: 0000000020ffd000 RBP: 000000000075c070 R08: 0000000000000004 R09: 0000000000000000 R10: 0000000000000011 R11: 0000000000000246 R12: 00007fdb3d6566d4 R13: 00000000004c5d1b R14: 00000000004da770 R15: 00000000ffffffff