INFO: task syz-executor.5:3414 blocked for more than 140 seconds. Not tainted 4.14.227-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28536 3414 7998 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 request_wait_answer+0x30d/0x620 fs/fuse/dev.c:478 __fuse_request_send+0x108/0x1a0 fs/fuse/dev.c:498 fuse_request_send fs/fuse/dev.c:511 [inline] fuse_simple_request+0x2fa/0x790 fs/fuse/dev.c:569 fuse_do_getattr+0x209/0xb60 fs/fuse/dir.c:920 fuse_update_get_attr fs/fuse/dir.c:945 [inline] fuse_update_get_attr fs/fuse/dir.c:937 [inline] fuse_getattr+0x2e1/0x500 fs/fuse/dir.c:1823 vfs_getattr_nosec+0xff/0x160 fs/stat.c:79 vfs_getattr fs/stat.c:116 [inline] vfs_statx+0x104/0x180 fs/stat.c:189 vfs_stat include/linux/fs.h:3065 [inline] SYSC_newstat fs/stat.c:337 [inline] SyS_newstat+0x83/0xe0 fs/stat.c:333 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x466459 RSP: 002b:00007fa2901bb188 EFLAGS: 00000246 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000020000040 RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffcd6db936f R14: 00007fa2901bb300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1531: #0: (tasklist_lock){.+.?}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by in:imklog/7693: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x1fb/0x2b0 fs/file.c:769 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1531 Comm: khungtaskd Not tainted 4.14.227-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: 4617 Comm: systemd-journal Not tainted 4.14.227-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a15a2680 task.stack: ffff8880a15a8000 RIP: 0033:0x7f23a21d9bff RSP: 002b:00007ffdf57bc3e0 EFLAGS: 00000202 RAX: 0000564aab13eeb0 RBX: 0000564aab13ee80 RCX: 0000000000000006 RDX: 0000000000000003 RSI: 0000000000000010 RDI: 0000000000000002 RBP: 0000564aab13b040 R08: 0000000000000000 R09: 0000000000133338 R10: 000b3cd399cf0620 R11: 00007f239feb8a18 R12: 0000564aab13ee80 R13: 00007ffdf57bc528 R14: 0000000000000010 R15: 00007ffdf57bc4b0 FS: 00007f23a25a18c0(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f239feb8018 CR3: 00000000a1ac9000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400