====================================================== WARNING: possible circular locking dependency detected 5.13.0-rc7-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.5/4874 is trying to acquire lock: ffff88808ed83928 (&mm->mmap_lock#2){++++}-{3:3}, at: __might_fault+0x91/0x110 mm/memory.c:5114 but task is already holding lock: ffff8880b9a3a338 (&cpuctx_mutex){+.+.}-{3:3}, at: perf_event_ctx_lock_nested+0x37a/0x4d0 kernel/events/core.c:1356 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&cpuctx_mutex){+.+.}-{3:3}: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5514 __mutex_lock_common+0x1bf/0x3100 kernel/locking/mutex.c:959 __mutex_lock kernel/locking/mutex.c:1104 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1119 perf_event_init_cpu+0x283/0x390 kernel/events/core.c:13231 perf_event_init+0xdb/0x140 kernel/events/core.c:13278 start_kernel+0x2c1/0x544 init/main.c:1001 secondary_startup_64_no_verify+0xb0/0xbb -> #2 (pmus_lock){+.+.}-{3:3}: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5514 __mutex_lock_common+0x1bf/0x3100 kernel/locking/mutex.c:959 __mutex_lock kernel/locking/mutex.c:1104 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1119 perf_event_init_cpu+0x1ce/0x390 kernel/events/core.c:13225 cpuhp_invoke_callback+0x4cc/0x850 kernel/cpu.c:179 cpuhp_invoke_callback_range kernel/cpu.c:654 [inline] cpuhp_up_callbacks kernel/cpu.c:682 [inline] _cpu_up+0x4c0/0xb70 kernel/cpu.c:1301 cpu_up+0x156/0x1a0 kernel/cpu.c:1336 bringup_nonboot_cpus+0xfc/0x1a0 kernel/cpu.c:1398 smp_init+0x32/0x14d kernel/smp.c:1090 kernel_init_freeable+0x3e4/0x58a init/main.c:1552 kernel_init+0xd/0x290 init/main.c:1447 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 -> #1 (cpu_hotplug_lock){++++}-{0:0}: lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5514 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] cpus_read_lock+0x40/0x120 kernel/cpu.c:297 __static_key_slow_dec+0x13/0x150 kernel/jump_label.c:254 sw_perf_event_destroy+0x91/0x190 kernel/events/core.c:9539 _free_event+0xd4d/0x12f0 kernel/events/core.c:4951 put_event kernel/events/core.c:5045 [inline] perf_mmap_close+0x8ed/0xe20 kernel/events/core.c:6090 remove_vma mm/mmap.c:186 [inline] remove_vma_list mm/mmap.c:2659 [inline] __do_munmap+0x1b45/0x2010 mm/mmap.c:2915 do_munmap mm/mmap.c:2923 [inline] munmap_vma_range mm/mmap.c:604 [inline] mmap_region+0x86f/0x1da0 mm/mmap.c:1756 do_mmap+0x964/0x11e0 mm/mmap.c:1587 vm_mmap_pgoff+0x19e/0x2b0 mm/util.c:519 ksys_mmap_pgoff+0x504/0x7b0 mm/mmap.c:1638 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #0 (&mm->mmap_lock#2){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:2940 [inline] check_prevs_add+0x4f9/0x5b60 kernel/locking/lockdep.c:3063 validate_chain kernel/locking/lockdep.c:3678 [inline] __lock_acquire+0x4307/0x6040 kernel/locking/lockdep.c:4904 lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5514 __might_fault+0xb4/0x110 mm/memory.c:5115 _copy_to_user+0x28/0x130 lib/usercopy.c:28 copy_to_user include/linux/uaccess.h:200 [inline] perf_read_one kernel/events/core.c:5324 [inline] __perf_read kernel/events/core.c:5367 [inline] perf_read+0x496/0x7d0 kernel/events/core.c:5384 vfs_read+0x294/0xc20 fs/read_write.c:494 ksys_read+0x171/0x2a0 fs/read_write.c:634 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: &mm->mmap_lock#2 --> pmus_lock --> &cpuctx_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&cpuctx_mutex); lock(pmus_lock); lock(&cpuctx_mutex); lock(&mm->mmap_lock#2); *** DEADLOCK *** 1 lock held by syz-executor.5/4874: #0: ffff8880b9a3a338 (&cpuctx_mutex){+.+.}-{3:3}, at: perf_event_ctx_lock_nested+0x37a/0x4d0 kernel/events/core.c:1356 stack backtrace: CPU: 1 PID: 4874 Comm: syz-executor.5 Not tainted 5.13.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x202/0x31e lib/dump_stack.c:120 print_circular_bug+0xb17/0xdc0 kernel/locking/lockdep.c:2009 check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2131 check_prev_add kernel/locking/lockdep.c:2940 [inline] check_prevs_add+0x4f9/0x5b60 kernel/locking/lockdep.c:3063 validate_chain kernel/locking/lockdep.c:3678 [inline] __lock_acquire+0x4307/0x6040 kernel/locking/lockdep.c:4904 lock_acquire+0x182/0x4a0 kernel/locking/lockdep.c:5514 __might_fault+0xb4/0x110 mm/memory.c:5115 _copy_to_user+0x28/0x130 lib/usercopy.c:28 copy_to_user include/linux/uaccess.h:200 [inline] perf_read_one kernel/events/core.c:5324 [inline] __perf_read kernel/events/core.c:5367 [inline] perf_read+0x496/0x7d0 kernel/events/core.c:5384 vfs_read+0x294/0xc20 fs/read_write.c:494 ksys_read+0x171/0x2a0 fs/read_write.c:634 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665d9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f04cc0d5188 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 0000000000001000 RSI: 00000000200000c0 RDI: 0000000000000004 RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007fff9ed5c37f R14: 00007f04cc0d5300 R15: 0000000000022000