RAX: ffffffffffffffda RBX: 00007f4a397786d4 RCX: 0000000000455ab9 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000016 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000017 R13: 00000000004bdc94 R14: 00000000004cc6d0 R15: 000000000000001c INFO: task syz-executor5:29871 blocked for more than 140 seconds. Not tainted 4.18.0-rc5-next-20180716+ #8 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D25408 29871 17239 0x00000004 Call Trace: context_switch kernel/sched/core.c:2849 [inline] __schedule+0x87c/0x1ea0 kernel/sched/core.c:3497 schedule+0xfb/0x450 kernel/sched/core.c:3541 __rwsem_down_write_failed_common+0x95d/0x1630 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0xaa/0x130 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:752 [inline] chmod_common+0x1b1/0x590 fs/open.c:535 do_fchmodat+0xc3/0x160 fs/open.c:579 __do_sys_chmod fs/open.c:597 [inline] __se_sys_chmod fs/open.c:595 [inline] __x64_sys_chmod+0x5c/0x80 fs/open.c:595 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455ab9 Code: e0 1f 48 89 04 24 e8 b6 6f fd ff e8 81 6a fd ff e8 5c 68 fd ff 48 8d 05 92 9a 48 00 48 89 04 24 48 c7 44 24 08 1d 00 00 00 e8 <13> 5e fd ff 0f 0b e8 8c 44 00 00 e9 07 f0 ff ff cc cc cc cc cc cc RSP: 002b:00007f41ae2e8c68 EFLAGS: 00000246 ORIG_RAX: 000000000000005a RAX: ffffffffffffffda RBX: 00007f41ae2e96d4 RCX: 0000000000455ab9 RDX: 0000000000000000 RSI: 00000000fffffff6 RDI: 00000000200006c0 RBP: 000000000072c098 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004bb0de R14: 00000000004c8c68 R15: 0000000000000003 INFO: lockdep is turned off. NMI backtrace for cpu 0 CPU: 0 PID: 902 Comm: khungtaskd Not tainted 4.18.0-rc5-next-20180716+ #8 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+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.3+0x48/0x88 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0xb39/0x10b0 kernel/hung_task.c:265 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.18.0-rc5-next-20180716+ #8 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:sched_ttwu_pending+0x0/0x270 kernel/sched/core.c:1593 Code: 4c 89 c7 e8 a2 ef 65 00 e9 dd fe ff ff e8 38 f0 65 00 4c 8b 85 70 ff ff ff e9 a9 fe ff ff 66 90 66 2e 0f 1f 84 00 00 00 00 00 <55> 48 89 e5 41 57 41 56 4c 8d b5 78 ff ff ff 41 55 49 c1 ee 03 49 RSP: 0018:ffff8801daf07ce8 EFLAGS: 00000002 RAX: 0000000000000007 RBX: 000000000002c980 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff816eda7b RDI: ffff8801d9b0eb8c RBP: ffff8801daf07e90 R08: 0000000000000000 R09: ffffed003b5e5a7c R10: ffffed003b5e5a7c R11: ffff8801daf2d3e3 R12: 000000000002c980 R13: 1ffff1003b5e0fa1 R14: ffff8801daf07e68 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7e0d019140 CR3: 00000001af47d000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: smp_reschedule_interrupt+0xf5/0x670 arch/x86/kernel/smp.c:277 reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:891 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 Code: c7 48 89 45 d8 e8 2a 0d 1d fa 48 8b 45 d8 e9 d2 fe ff ff 48 89 df e8 19 0d 1d fa eb 8a 90 90 90 90 90 90 90 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 90 90 90 90 90 RSP: 0018:ffff8801d9b1fc38 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: 1ffff1003b363f8a RCX: ffffffff8166ab32 RDX: 1ffffffff11e3650 RSI: 0000000000000004 RDI: ffffffff88f1b280 RBP: ffff8801d9b1fc38 R08: ffffed003b5e46d7 R09: ffffed003b5e46d6 R10: ffffed003b5e46d6 R11: ffff8801daf236b3 R12: 0000000000000001 R13: ffff8801d9b1fcf0 R14: ffffffff899f37a0 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0xc7/0x450 arch/x86/kernel/process.c:500 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:491 default_idle_call+0x6d/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x3aa/0x570 kernel/sched/idle.c:262 cpu_startup_entry+0x10c/0x120 kernel/sched/idle.c:368 start_secondary+0x433/0x5d0 arch/x86/kernel/smpboot.c:270 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242