INFO: task syz-executor2:6014 blocked for more than 140 seconds. Not tainted 5.0.0-rc4 #49 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D20440 6014 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2844 [inline] __schedule+0x897/0x1e60 kernel/sched/core.c:3485 schedule+0xfe/0x350 kernel/sched/core.c:3529 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3587 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xa3b/0x1670 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 fuse_lock_inode+0xba/0xf0 fs/fuse/inode.c:364 fuse_lookup+0x8e/0x380 fs/fuse/dir.c:350 __lookup_slow+0x2cd/0x560 fs/namei.c:1671 lookup_slow+0x58/0x80 fs/namei.c:1688 walk_component+0x8e5/0x26a0 fs/namei.c:1810 link_path_walk.part.0+0xa57/0x1550 fs/namei.c:2141 link_path_walk fs/namei.c:2072 [inline] path_mountpoint+0xf0/0x21a0 fs/namei.c:2694 filename_mountpoint+0x258/0x490 fs/namei.c:2717 user_path_mountpoint_at+0x3a/0x50 fs/namei.c:2747 ksys_umount+0x198/0x1340 fs/namespace.c:1643 __do_sys_umount fs/namespace.c:1669 [inline] __se_sys_umount fs/namespace.c:1667 [inline] __x64_sys_umount+0x54/0x80 fs/namespace.c:1667 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45aae7 Code: 39 3b 75 8c 48 89 23 eb 87 cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 8b 71 10 48 81 fe de fa ff ff 0f 84 90 <00> 00 00 48 8d 84 24 70 03 00 00 48 29 f0 48 3d f8 02 04 00 76 7d RSP: 002b:00007ffc5703eca8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00000000000f36f7 RCX: 000000000045aae7 RDX: 0000000000402eb0 RSI: 0000000000000002 RDI: 00007ffc5703ed50 RBP: 000000000000000f R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000006 R11: 0000000000000202 R12: 00007ffc5703fde0 R13: 0000000001431940 R14: 0000000000000000 R15: 0000000000000002 Showing all locks held in the system: 1 lock held by khungtaskd/1040: #0: 00000000c0e2bff1 (rcu_read_lock){....}, at: debug_show_all_locks+0xc6/0x41d kernel/locking/lockdep.c:4389 1 lock held by rsyslogd/7896: #0: 0000000047c8a126 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1b3/0x1f0 fs/file.c:795 2 locks held by getty/7986: #0: 00000000943708be (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000cf035cf6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7987: #0: 0000000013b0395d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000e148326a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7988: #0: 000000006f130e9b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000f9868900 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7989: #0: 000000001fe628fd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000064256a28 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7990: #0: 00000000f3999472 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000003fe24d21 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7991: #0: 000000002a1b9dfd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000cd859f0d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7992: #0: 00000000d25b11bd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000c76765df (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by syz-executor2/6014: #0: 00000000f2c693b3 (&type->i_mutex_dir_key#9){++++}, at: inode_lock_shared include/linux/fs.h:767 [inline] #0: 00000000f2c693b3 (&type->i_mutex_dir_key#9){++++}, at: lookup_slow+0x4a/0x80 fs/namei.c:1687 #1: 000000007a1d5151 (&fi->mutex){+.+.}, at: fuse_lock_inode+0xba/0xf0 fs/fuse/inode.c:364 2 locks held by syz-executor2/6129: #0: 00000000f2c693b3 (&type->i_mutex_dir_key#9){++++}, at: inode_lock_shared include/linux/fs.h:767 [inline] #0: 00000000f2c693b3 (&type->i_mutex_dir_key#9){++++}, at: lookup_slow+0x4a/0x80 fs/namei.c:1687 #1: 000000007a1d5151 (&fi->mutex){+.+.}, at: fuse_lock_inode+0xba/0xf0 fs/fuse/inode.c:364 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1040 Comm: khungtaskd Not tainted 5.0.0-rc4 #49 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+0x1db/0x2d0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0xbbb/0x1170 kernel/hung_task.c:287 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x2/0x10 arch/x86/include/asm/irqflags.h:57