INFO: task syz-executor417:8900 blocked for more than 140 seconds. Not tainted 4.14.265-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor417 D28912 8900 7981 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: e2d0141c:0x7ffd41c5bc30 RSP: 0064:0000000000000032 EFLAGS: 7ffd41c5bc10 INFO: task syz-executor417:8901 blocked for more than 140 seconds. Not tainted 4.14.265-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor417 D28984 8901 7981 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: 0033:0x7f3ee2c79b39 RSP: 002b:00007f3ee2c2b318 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f3ee2d01408 RCX: 00007f3ee2c79b39 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f3ee2d01408 RBP: 00007f3ee2d01400 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3ee2ccf074 R13: 00007ffd41c5bb5f R14: 00007f3ee2c2b400 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-executor417/8900: #0: (&mm->mmap_sem){++++}, at: [] __do_page_fault+0x7b8/0xad0 arch/x86/mm/fault.c:1378 1 lock held by syz-executor417/8901: #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 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1533 Comm: khungtaskd Not tainted 4.14.265-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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8902 Comm: syz-executor417 Not tainted 4.14.265-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880aff9a300 task.stack: ffff8880a0160000 RIP: 0010:arch_local_save_flags arch/x86/include/asm/paravirt.h:774 [inline] RIP: 0010:___might_sleep+0x155/0x2b0 kernel/sched/core.c:6008 RSP: 0018:ffff8880a0167aa0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 1ffff11015ff34d0 RSI: 00000000ffffffff RDI: ffff8880aff9a680 RBP: ffffffff8789d300 R08: ffffffff8165919a R09: dffffc0000000000 R10: 0000000000000000 R11: ffff8880aff9a300 R12: 00000000000002eb R13: 0000000000000000 R14: ffff8880aff9a300 R15: ffffffff8165919a FS: 00007f3ee2c0a700(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd41c5bbb8 CR3: 00000000b428a000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __mutex_lock_common kernel/locking/mutex.c:747 [inline] __mutex_lock+0x98/0x1310 kernel/locking/mutex.c:893 perf_mmap+0x50a/0x1390 kernel/events/core.c:5423 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: 0033:0x7f3ee2c79b39 RSP: 002b:00007f3ee2c0a308 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f3ee2d01418 RCX: 00007f3ee2c79b39 RDX: 0000000000000000 RSI: 0000000000002000 RDI: 0000000020395000 RBP: 00007f3ee2d01410 R08: 0000000000000003 R09: 0000000000000000 R10: 0000000000000011 R11: 0000000000000246 R12: 00007f3ee2ccf074 R13: 00007ffd41c5bb5f R14: 00007f3ee2c0a400 R15: 0000000000022000 Code: 05 d1 b2 a7 07 48 8b 15 8a 59 f6 09 48 83 e8 64 48 39 d0 0f 89 60 cd c8 05 48 85 d2 0f 84 57 cd c8 05 5b 5d 41 5c 41 5d 41 5e c3 <48> c7 c0 c0 93 f0 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 ---------------- Code disassembly (best guess): 0: 05 d1 b2 a7 07 add $0x7a7b2d1,%eax 5: 48 8b 15 8a 59 f6 09 mov 0x9f6598a(%rip),%rdx # 0x9f65996 c: 48 83 e8 64 sub $0x64,%rax 10: 48 39 d0 cmp %rdx,%rax 13: 0f 89 60 cd c8 05 jns 0x5c8cd79 19: 48 85 d2 test %rdx,%rdx 1c: 0f 84 57 cd c8 05 je 0x5c8cd79 22: 5b pop %rbx 23: 5d pop %rbp 24: 41 5c pop %r12 26: 41 5d pop %r13 28: 41 5e pop %r14 2a: c3 retq * 2b: 48 c7 c0 c0 93 f0 88 mov $0xffffffff88f093c0,%rax <-- trapping instruction 32: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 39: fc ff df 3c: 48 c1 e8 03 shr $0x3,%rax