INFO: task syz-executor387:12637 blocked for more than 140 seconds. Not tainted 4.14.282-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor387 D28912 12637 7995 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: 0001:0x7f83202e81a0 RSP: 202df198:0000000000000000 EFLAGS: 00000000 INFO: task syz-executor387:12638 blocked for more than 140 seconds. Not tainted 4.14.282-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor387 D29048 12638 7995 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: 0033:0x7f83202592c9 RSP: 002b:00007f8320207308 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 0000000000000000 RCX: 00007f83202592c9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f83202e14c8 RBP: 00007f83202e14c8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f83202e14c0 R13: 00007f83202ae4a4 R14: 00007f8320207400 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 in:imklog/7683: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x1fb/0x2b0 fs/file.c:819 1 lock held by syz-executor387/12637: #0: (&mm->mmap_sem){++++}, at: [] __do_page_fault+0x7b8/0xad0 arch/x86/mm/fault.c:1378 1 lock held by syz-executor387/12638: #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-executor387/28671: #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 1 lock held by syz-executor387/28678: #0: (&mm->mmap_sem){++++}, at: [] vm_mmap_pgoff+0x11e/0x1a0 mm/util.c:331 1 lock held by syz-executor387/28680: #0: (&mm->mmap_sem){++++}, at: [] vm_mmap_pgoff+0x11e/0x1a0 mm/util.c:331 2 locks held by syz-executor387/28675: #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 1 lock held by syz-executor387/28682: #0: (&mm->mmap_sem){++++}, at: [] vm_mmap_pgoff+0x11e/0x1a0 mm/util.c:331 3 locks held by syz-executor387/28683: #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 1 lock held by syz-executor387/28684: #0: (&mm->mmap_sem){++++}, at: [] vm_mmap_pgoff+0x11e/0x1a0 mm/util.c:331 3 locks held by syz-executor387/28685: #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:272 [inline] #2: (rcu_preempt_state.exp_mutex){+.+.}, at: [] _synchronize_rcu_expedited+0x2c2/0x770 kernel/rcu/tree_exp.h:596 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1533 Comm: khungtaskd Not tainted 4.14.282-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: 8981 Comm: kworker/0:3 Not tainted 4.14.282-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events wait_rcu_exp_gp task: ffff88809112c6c0 task.stack: ffff88808e910000 RIP: 0010:debug_lockdep_rcu_enabled kernel/rcu/update.c:300 [inline] RIP: 0010:debug_lockdep_rcu_enabled+0x76/0xe0 kernel/rcu/update.c:297 RSP: 0018:ffff88808e917a90 EFLAGS: 00000002 RAX: 0000000000000003 RBX: ffff88809112c6c0 RCX: 0000000000000001 RDX: 0000000000000004 RSI: 0000000000000002 RDI: ffff88809112cf44 RBP: ffffffff893d57d8 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002001d008 CR3: 00000000a7d44000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x307/0x3f0 kernel/locking/lockdep.c:3997 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:160 free_object+0x1b/0x240 lib/debugobjects.c:223 destroy_timer_on_stack kernel/time/timer.c:724 [inline] schedule_timeout+0x4c6/0xe90 kernel/time/timer.c:1751 synchronize_sched_expedited_wait kernel/rcu/tree_exp.h:450 [inline] rcu_exp_wait_wake+0x13d/0x520 kernel/rcu/tree_exp.h:518 process_one_work+0x793/0x14a0 kernel/workqueue.c:2117 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 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 37 06 f7 07 85 c9 74 45 65 48 8b 1c 25 c0 7f 02 00 <48> 8d bb 84 08 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 ---------------- Code disassembly (best guess): 0: 89 c1 mov %eax,%ecx 2: 83 e0 07 and $0x7,%eax 5: 48 c1 e9 03 shr $0x3,%rcx 9: 83 c0 03 add $0x3,%eax c: 0f b6 14 11 movzbl (%rcx,%rdx,1),%edx 10: 38 d0 cmp %dl,%al 12: 7c 04 jl 0x18 14: 84 d2 test %dl,%dl 16: 75 64 jne 0x7c 18: 8b 0d 37 06 f7 07 mov 0x7f70637(%rip),%ecx # 0x7f70655 1e: 85 c9 test %ecx,%ecx 20: 74 45 je 0x67 22: 65 48 8b 1c 25 c0 7f mov %gs:0x27fc0,%rbx 29: 02 00 * 2b: 48 8d bb 84 08 00 00 lea 0x884(%rbx),%rdi <-- trapping instruction 32: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 39: fc ff df 3c: 48 89 fa mov %rdi,%rdx 3f: 48 rex.W