kworker/dying (97) used greatest stack depth: 9528 bytes left INFO: task syz-executor5:26887 blocked for more than 140 seconds. Not tainted 4.18.0-rc6+ #160 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D24672 26887 4578 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3603 __mutex_lock_common kernel/locking/mutex.c:834 [inline] __mutex_lock+0xede/0x1820 kernel/locking/mutex.c:894 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:909 fuse_lock_inode+0xaf/0xe0 fs/fuse/inode.c:363 fuse_lookup+0x8f/0x4c0 fs/fuse/dir.c:359 __lookup_slow+0x2b5/0x540 fs/namei.c:1630 lookup_slow+0x57/0x80 fs/namei.c:1647 walk_component+0x94a/0x2630 fs/namei.c:1769 lookup_last fs/namei.c:2237 [inline] path_lookupat.isra.45+0x202/0xbf0 fs/namei.c:2287 filename_lookup+0x264/0x510 fs/namei.c:2321 user_path_at_empty+0x40/0x50 fs/namei.c:2584 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0x129/0x210 fs/stat.c:185 vfs_lstat include/linux/fs.h:3107 [inline] __do_sys_newlstat+0x8f/0x110 fs/stat.c:350 __se_sys_newlstat fs/stat.c:344 [inline] __x64_sys_newlstat+0x54/0x80 fs/stat.c:344 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 23 cd 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:00007fd40153cc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000006 RAX: ffffffffffffffda RBX: 00007fd40153d6d4 RCX: 0000000000455ab9 RDX: 0000000000000000 RSI: 0000000020000340 RDI: 0000000020000000 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004c00fa R14: 00000000004cfbf8 R15: 0000000000000000 INFO: task syz-executor5:26942 blocked for more than 140 seconds. Not tainted 4.18.0-rc6+ #160 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D22920 26942 4578 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 request_wait_answer+0x4c8/0x920 fs/fuse/dev.c:463 __fuse_request_send+0x12a/0x1d0 fs/fuse/dev.c:483 fuse_request_send+0x62/0xa0 fs/fuse/dev.c:496 fuse_simple_request+0x33d/0x730 fs/fuse/dev.c:554 fuse_lookup_name+0x3ee/0x830 fs/fuse/dir.c:323 fuse_lookup+0xf9/0x4c0 fs/fuse/dir.c:360 fuse_atomic_open+0x214/0x350 fs/fuse/dir.c:499 atomic_open fs/namei.c:3054 [inline] lookup_open+0xdb1/0x1b40 fs/namei.c:3190 do_last fs/namei.c:3311 [inline] path_openat+0x207d/0x4e10 fs/namei.c:3540 do_filp_open+0x255/0x380 fs/namei.c:3574 do_open_execat+0x1fe/0x670 fs/exec.c:852 __do_execve_file.isra.35+0x1750/0x25b0 fs/exec.c:1753 do_execveat_common fs/exec.c:1864 [inline] do_execve fs/exec.c:1881 [inline] __do_sys_execve fs/exec.c:1962 [inline] __se_sys_execve fs/exec.c:1957 [inline] __x64_sys_execve+0x8f/0xc0 fs/exec.c:1957 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 23 cd 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:00007fd4014d9c68 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00007fd4014da6d4 RCX: 0000000000455ab9 RDX: 00000000200004c0 RSI: 00000000200001c0 RDI: 0000000020000040 RBP: 000000000072c0b0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004bba4b R14: 00000000004c90b8 R15: 0000000000000003 Showing all locks held in the system: 1 lock held by khungtaskd/901: #0: 000000005d195d30 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 1 lock held by rsyslogd/4430: 2 locks held by getty/4520: #0: 00000000ef680e73 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000c4fe3e5e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4521: #0: 0000000056d6291a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000001530e1c5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4522: #0: 000000004f1bae32 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000bbb4ffc7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4523: #0: 00000000573c222c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000db768d86 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4524: #0: 00000000f2e91eeb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000007b852fb3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4525: #0: 000000006a3ae9e8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000009eaabd36 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4526: #0: 00000000b772a6a9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000098577983 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor5/26887: #0: 000000007b355e62 (&type->i_mutex_dir_key#5){++++}, at: inode_lock_shared include/linux/fs.h:725 [inline] #0: 000000007b355e62 (&type->i_mutex_dir_key#5){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1646 #1: 000000004d647d2c (&fi->mutex){+.+.}, at: fuse_lock_inode+0xaf/0xe0 fs/fuse/inode.c:363 3 locks held by syz-executor5/26942: #0: 000000000f395809 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds+0x53/0x120 fs/exec.c:1402 #1: 000000007b355e62 (&type->i_mutex_dir_key#5){++++}, at: inode_lock_shared include/linux/fs.h:725 [inline] #1: 000000007b355e62 (&type->i_mutex_dir_key#5){++++}, at: do_last fs/namei.c:3310 [inline] #1: 000000007b355e62 (&type->i_mutex_dir_key#5){++++}, at: path_openat+0x204c/0x4e10 fs/namei.c:3540 #2: 000000004d647d2c (&fi->mutex){+.+.}, at: fuse_lock_inode+0xaf/0xe0 fs/fuse/inode.c:363 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 901 Comm: khungtaskd Not tainted 4.18.0-rc6+ #160 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.4+0x19/0xce lib/nmi_backtrace.c:103 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:138 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline] watchdog+0x9c4/0xf80 kernel/hung_task.c:252 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54