INFO: task syz-executor306:24180 blocked for more than 140 seconds. Not tainted 4.14.276-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor306 D28416 24180 7979 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] rwsem_down_read_failed+0x1e6/0x350 kernel/locking/rwsem-xadd.c:309 call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:66 [inline] down_read+0x44/0x80 kernel/locking/rwsem.c:26 __do_page_fault+0x7b8/0xad0 arch/x86/mm/fault.c:1378 page_fault+0x45/0x50 arch/x86/entry/entry_64.S:1123 RIP: 0001:0x7f5ad0fc7100 RSP: d0fc0198:0000000000000000 EFLAGS: 00000000 INFO: task syz-executor306:24181 blocked for more than 140 seconds. Not tainted 4.14.276-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor306 D28920 24181 7979 0x80000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] rwsem_down_read_failed+0x1e6/0x350 kernel/locking/rwsem-xadd.c:309 call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:66 [inline] down_read+0x44/0x80 kernel/locking/rwsem.c:26 exit_mm kernel/exit.c:511 [inline] do_exit+0x598/0x2850 kernel/exit.c:855 do_group_exit+0x100/0x2e0 kernel/exit.c:965 get_signal+0x38d/0x1ca0 kernel/signal.c:2412 do_signal+0x7c/0x1550 arch/x86/kernel/signal.c:792 exit_to_usermode_loop+0x160/0x200 arch/x86/entry/common.c:160 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 RIP: 0033:0x7f5ad0f39439 RSP: 002b:00007f5ad0eea308 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f5ad0fc24c8 RCX: 00007f5ad0f39439 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f5ad0fc24c8 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5ad0fc24c0 R13: 00007f5ad0f8f088 R14: 0000000000000000 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1533: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by syz-executor306/24180: #0: (&mm->mmap_sem){++++}, at: [] __do_page_fault+0x7b8/0xad0 arch/x86/mm/fault.c:1378 1 lock held by syz-executor306/24181: #0: (&mm->mmap_sem){++++}, at: [] exit_mm kernel/exit.c:511 [inline] #0: (&mm->mmap_sem){++++}, at: [] do_exit+0x598/0x2850 kernel/exit.c:855 1 lock held by syz-executor306/16043: #0: (&mm->mmap_sem){++++}, at: [] __do_page_fault+0x7b8/0xad0 arch/x86/mm/fault.c:1378 1 lock held by syz-executor306/16044: #0: (&mm->mmap_sem){++++}, at: [] exit_mm kernel/exit.c:511 [inline] #0: (&mm->mmap_sem){++++}, at: [] do_exit+0x598/0x2850 kernel/exit.c:855 2 locks held by syz-executor306/28729: #0: (&ctx->mutex){+.+.}, at: [] perf_event_ctx_lock_nested+0x14d/0x2c0 kernel/events/core.c:1241 #1: (&event->mmap_mutex){+.+.}, at: [] perf_event_set_output+0x267/0x450 kernel/events/core.c:9908 3 locks held by syz-executor306/28724: #0: (&mm->mmap_sem){++++}, at: [] vm_mmap_pgoff+0x11e/0x1a0 mm/util.c:331 #1: (&event->mmap_mutex){+.+.}, at: [] perf_mmap+0x50a/0x1390 kernel/events/core.c:5423 #2: (rcu_preempt_state.exp_mutex){+.+.}, at: [] exp_funnel_lock kernel/rcu/tree_exp.h:305 [inline] #2: (rcu_preempt_state.exp_mutex){+.+.}, at: [] _synchronize_rcu_expedited+0x32d/0x770 kernel/rcu/tree_exp.h:596 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1533 Comm: khungtaskd Not tainted 4.14.276-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 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 24196 Comm: syz-executor306 Not tainted 4.14.276-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88809b8c2200 task.stack: ffff8880a9d70000 RIP: 0010:debug_lockdep_rcu_enabled+0x5b/0xe0 kernel/rcu/update.c:299 RSP: 0018:ffff8880a9d77af0 EFLAGS: 00000006 RAX: 0000000000000003 RBX: 1ffff110153aef63 RCX: 1ffffffff127a4f8 RDX: 0000000000000004 RSI: 0000000000000002 RDI: ffff88809b8c2a84 RBP: ffff88809969a980 R08: 0000000000000000 R09: 000000000004058f R10: 0000000000000000 R11: ffff88809b8c2200 R12: ffffffff81659c25 R13: ffff88809b8c2200 R14: ffff8880a9d77bd0 R15: 0000000000000000 FS: 00007f5ad0ec9700(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb2f9010000 CR3: 000000009a053000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x5a6/0x870 kernel/locking/lockdep.c:4016 __mutex_unlock_slowpath+0x75/0x770 kernel/locking/mutex.c:1018 perf_mmap+0x635/0x1390 kernel/events/core.c:5436 call_mmap include/linux/fs.h:1785 [inline] mmap_region+0xa1a/0x1220 mm/mmap.c:1717 do_mmap+0x5b3/0xcb0 mm/mmap.c:1495 do_mmap_pgoff include/linux/mm.h:2185 [inline] vm_mmap_pgoff+0x14e/0x1a0 mm/util.c:333 SYSC_mmap_pgoff mm/mmap.c:1545 [inline] SyS_mmap_pgoff+0x249/0x510 mm/mmap.c:1503 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f5ad0f39439 RSP: 002b:00007f5ad0ec92f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f5ad0fc24d8 RCX: 00007f5ad0f39439 RDX: 0000000000000000 RSI: 0000000000002000 RDI: 0000000020395000 RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000000 R10: 0000000000000011 R11: 0000000000000246 R12: 00007f5ad0fc24d0 R13: 00007f5ad0f8f088 R14: 00007f5ad0fc0130 R15: 0000000000022000 Code: 35 6f 35 c3 08 85 f6 74 79 48 c7 c0 c0 27 3d 89 48 ba 00 00 00 00 00 fc ff df 48 89 c1 83 e0 07 48 c1 e9 03 83 c0 03 0f b6 14 11 <38> d0 7c 04 84 d2 75 64 8b 0d b7 05 f7 07 85 c9 74 45 65 48 8b ---------------- Code disassembly (best guess): 0: 35 6f 35 c3 08 xor $0x8c3356f,%eax 5: 85 f6 test %esi,%esi 7: 74 79 je 0x82 9: 48 c7 c0 c0 27 3d 89 mov $0xffffffff893d27c0,%rax 10: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 17: fc ff df 1a: 48 89 c1 mov %rax,%rcx 1d: 83 e0 07 and $0x7,%eax 20: 48 c1 e9 03 shr $0x3,%rcx 24: 83 c0 03 add $0x3,%eax 27: 0f b6 14 11 movzbl (%rcx,%rdx,1),%edx * 2b: 38 d0 cmp %dl,%al <-- trapping instruction 2d: 7c 04 jl 0x33 2f: 84 d2 test %dl,%dl 31: 75 64 jne 0x97 33: 8b 0d b7 05 f7 07 mov 0x7f705b7(%rip),%ecx # 0x7f705f0 39: 85 c9 test %ecx,%ecx 3b: 74 45 je 0x82 3d: 65 gs 3e: 48 rex.W 3f: 8b .byte 0x8b