INFO: task syz-executor4:27567 blocked for more than 140 seconds. Not tainted 4.19.0+ #86 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D25376 27567 5828 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3480 schedule+0xfe/0x460 kernel/sched/core.c:3524 request_wait_answer+0x4a6/0x900 fs/fuse/dev.c:474 __fuse_request_send+0x12a/0x1d0 fs/fuse/dev.c:494 fuse_request_send+0x62/0xa0 fs/fuse/dev.c:507 fuse_simple_request+0x33d/0x730 fs/fuse/dev.c:565 fuse_listxattr+0x421/0x840 fs/fuse/xattr.c:139 vfs_listxattr+0x114/0x1a0 fs/xattr.c:355 listxattr+0x74/0x150 fs/xattr.c:617 path_listxattr+0xf5/0x1a0 fs/xattr.c:641 __do_sys_llistxattr fs/xattr.c:659 [inline] __se_sys_llistxattr fs/xattr.c:656 [inline] __x64_sys_llistxattr+0x75/0xb0 fs/xattr.c:656 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: 83 c4 18 c3 e8 d8 64 00 00 48 8b 04 24 48 8b 4c 24 08 48 89 01 e8 d7 2d fc ff e8 22 7a fc ff b8 02 00 00 00 48 8d 0d ca 96 0a <01> 87 01 8b 05 c2 96 0a 01 83 f8 01 0f 85 8a 00 00 00 b8 01 00 00 RSP: 002b:00007f95daf60c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000c3 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569 RDX: 00000000000000de RSI: 0000000020000480 RDI: 0000000020000240 RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f95daf616d4 R13: 00000000004c292e R14: 00000000004d3d58 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1008: #0: 0000000031d7b139 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5594: #0: 00000000d89cb4a7 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5685: #0: 000000007fbeedba (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000dd3c6696 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5686: #0: 00000000cb8bdc80 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000008569df9e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5687: #0: 0000000061629992 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000c9e0e946 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5688: #0: 00000000a1a36470 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e4150667 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5689: #0: 000000001c80443a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000a9569321 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5690: #0: 00000000dee26d41 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000033657050 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5691: #0: 00000000c480b188 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000072ce801b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1008 Comm: khungtaskd Not tainted 4.19.0+ #86 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+0x244/0x39d lib/dump_stack.c:113 nmi_cpu_backtrace.cold.1+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x1ed 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+0xb3e/0x1050 kernel/hung_task.c:265 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:350 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.0+ #86 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:_nohz_idle_balance+0x0/0x7a0 kernel/sched/fair.c:9074 Code: ff ff e8 03 ad 66 00 4c 8b 8d 48 fe ff ff 4c 8b 95 60 fe ff ff 48 8b 8d 68 fe ff ff e9 e8 f9 ff ff 66 0f 1f 84 00 00 00 00 00 <55> 48 89 e5 41 57 48 8d 85 38 fe ff ff 41 56 41 55 4c 8d 7d d8 48 RSP: 0018:ffff8801daf079e0 EFLAGS: 00000246 RAX: 0000000000000003 RBX: ffff8801daf2ccc0 RCX: ffffffff815bf3a8 RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff8801daf2ccc0 RBP: ffff8801daf07ad8 R08: 1ffff1003b5e0f46 R09: ffffed003b5e59a9 R10: ffffed003b5e59a9 R11: ffff8801daf2cd4b R12: 1ffff1003b5e0f42 R13: ffff8801daf07ab0 R14: ffff8801daf2ccc0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001d8e0f000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __do_softirq+0x308/0xb7e kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x17f/0x1c0 kernel/softirq.c:413 scheduler_ipi+0x55a/0xad0 kernel/sched/core.c:1785 smp_reschedule_interrupt+0x109/0x650 arch/x86/kernel/smp.c:278 reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:825 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57 Code: e9 2c ff ff ff 48 89 c7 48 89 45 d8 e8 d3 e5 f5 f9 48 8b 45 d8 e9 ca fe ff ff 48 89 df e8 c2 e5 f5 f9 eb 82 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:ffff8801d9af7cb8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: 1ffff1003b35ef9b RCX: 0000000000000000 RDX: 1ffffffff12a3f49 RSI: 0000000000000001 RDI: ffffffff8951fa48 RBP: ffff8801d9af7cb8 R08: ffff8801d9ae8340 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d9af7d78 R13: ffffffff8a14a8a0 R14: 0000000000000000 R15: 0000000000000001 arch_safe_halt arch/x86/include/asm/paravirt.h:151 [inline] default_idle+0xbf/0x490 arch/x86/kernel/process.c:498 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:489 default_idle_call+0x6d/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x49b/0x5c0 kernel/sched/idle.c:262 cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:353 start_secondary+0x487/0x5f0 arch/x86/kernel/smpboot.c:271 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243