INFO: task syz-executor.3:7123 blocked for more than 140 seconds. Not tainted 4.14.114 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D24992 7123 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 fuse_lock_inode+0xbc/0xf0 fs/fuse/inode.c:365 fuse_lookup+0x7a/0x380 fs/fuse/dir.c:360 lookup_slow+0x22c/0x440 fs/namei.c:1695 walk_component+0x69d/0x1d00 fs/namei.c:1824 link_path_walk+0x81f/0x10b0 fs/namei.c:2153 path_mountpoint+0xac/0x1970 fs/namei.c:2717 filename_mountpoint+0x16c/0x320 fs/namei.c:2744 user_path_mountpoint_at+0x3a/0x50 fs/namei.c:2774 SYSC_umount fs/namespace.c:1730 [inline] SyS_umount+0x10c/0x380 fs/namespace.c:1714 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45b7f7 RSP: 002b:00007ffefcd08618 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00000000000bf120 RCX: 000000000045b7f7 RDX: 00000000004032d0 RSI: 0000000000000002 RDI: 00007ffefcd086c0 RBP: 0000000000000c9d R08: 0000000000000000 R09: 0000000000000011 R10: 000000000000000a R11: 0000000000000202 R12: 00007ffefcd09750 R13: 0000000001b1f940 R14: 0000000000000000 R15: 00007ffefcd09750 Showing all locks held in the system: 1 lock held by khungtaskd/1008: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4541 1 lock held by rsyslogd/6952: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0xab/0xd0 fs/file.c:769 2 locks held by getty/7074: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/7075: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/7076: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/7077: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/7078: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/7079: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/7080: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.3/7123: #0: (&type->i_mutex_dir_key#7){++++}, at: [] inode_lock_shared include/linux/fs.h:725 [inline] #0: (&type->i_mutex_dir_key#7){++++}, at: [] lookup_slow+0x138/0x440 fs/namei.c:1673 #1: (&fi->mutex){+.+.}, at: [] fuse_lock_inode+0xbc/0xf0 fs/fuse/inode.c:365 2 locks held by syz-executor.3/31936: #0: (&type->i_mutex_dir_key#7){++++}, at: [] inode_lock_shared include/linux/fs.h:725 [inline] #0: (&type->i_mutex_dir_key#7){++++}, at: [] lookup_slow+0x138/0x440 fs/namei.c:1673 #1: (&fi->mutex){+.+.}, at: [] fuse_lock_inode+0xbc/0xf0 fs/fuse/inode.c:365 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1008 Comm: khungtaskd Not tainted 4.14.114 #4 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+0x138/0x19c lib/dump_stack.c:53 nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x141/0x189 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:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5e7/0xb90 kernel/hung_task.c:274 kthread+0x31c/0x430 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2245 Comm: kworker/u4:4 Not tainted 4.14.114 #4 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker task: ffff8880a1e48680 task.stack: ffff8880a1e50000 RIP: 0010:check_preemption_disabled+0x44/0x250 lib/smp_processor_id.c:53 RSP: 0018:ffff8880a1e57c90 EFLAGS: 00000286 RAX: 0000000000000001 RBX: ffff88809f9a6c40 RCX: 1ffffffff0f56424 RDX: 0000000000000000 RSI: ffffffff869d1e40 RDI: ffffffff869d1e80 RBP: ffff8880a1e57cb0 R08: 0000000000000000 R09: ffff8880a1e48f70 R10: ffff8880a1e48f50 R11: ffff8880a1e48680 R12: 0000000000000001 R13: ffffffff869d1e40 R14: ffffffff869d1e80 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd133feb140 CR3: 00000000a5209000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_smp_processor_id+0x1c/0x20 lib/smp_processor_id.c:57 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:360 [inline] rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:1130 rcu_read_unlock include/linux/rcupdate.h:683 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:420 [inline] batadv_nc_worker+0x40a/0x6d0 net/batman-adv/network-coding.c:726 process_one_work+0x868/0x1610 kernel/workqueue.c:2114 worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248 kthread+0x31c/0x430 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 Code: a6 84 fe 65 44 8b 25 0c 3f 29 7d 65 8b 05 a5 ab 29 7d a9 ff ff ff 7f 74 1c e8 79 a6 84 fe e8 74 a6 84 fe 44 89 e0 48 83 c4 08 5b <41> 5c 41 5d 41 5e 41 5f 5d c3 e8 5d a6 84 fe 48 c7 c0 60 4b 71