INFO: task syz-executor0:9211 blocked for more than 140 seconds. Not tainted 4.19.0+ #81 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D24072 9211 5623 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3474 schedule+0xfe/0x460 kernel/sched/core.c:3518 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_lookup_name+0x3ee/0x830 fs/fuse/dir.c:323 fuse_lookup+0xff/0x4c0 fs/fuse/dir.c:361 __lookup_slow+0x2b5/0x540 fs/namei.c:1671 lookup_slow+0x57/0x80 fs/namei.c:1688 walk_component+0x92b/0x2590 fs/namei.c:1810 lookup_last fs/namei.c:2273 [inline] path_lookupat.isra.43+0x212/0xc00 fs/namei.c:2318 filename_lookup+0x26a/0x520 fs/namei.c:2348 user_path_at_empty+0x40/0x50 fs/namei.c:2608 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0x129/0x210 fs/stat.c:185 vfs_lstat include/linux/fs.h:3118 [inline] __do_sys_newlstat+0x8f/0x110 fs/stat.c:352 __se_sys_newlstat fs/stat.c:346 [inline] __x64_sys_newlstat+0x54/0x80 fs/stat.c:346 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 2a 60 09 <01> 87 01 8b 05 22 60 09 01 83 f8 01 0f 85 8a 00 00 00 b8 01 00 00 RSP: 002b:00007f45af16ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000006 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457569 RDX: 0000000000000000 RSI: 0000000020000340 RDI: 0000000020000000 RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f45af16f6d4 R13: 00000000004c279a R14: 00000000004d3a38 R15: 00000000ffffffff INFO: task syz-executor0:9223 blocked for more than 140 seconds. Not tainted 4.19.0+ #81 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D24528 9223 5623 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3474 schedule+0xfe/0x460 kernel/sched/core.c:3518 d_wait_lookup fs/dcache.c:2428 [inline] d_alloc_parallel+0x1478/0x1f40 fs/dcache.c:2510 __lookup_slow+0x1e6/0x540 fs/namei.c:1654 lookup_slow+0x57/0x80 fs/namei.c:1688 walk_component+0x92b/0x2590 fs/namei.c:1810 lookup_last fs/namei.c:2273 [inline] path_lookupat.isra.43+0x212/0xc00 fs/namei.c:2318 filename_lookup+0x26a/0x520 fs/namei.c:2348 user_path_at_empty+0x40/0x50 fs/namei.c:2608 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0x129/0x210 fs/stat.c:185 vfs_lstat include/linux/fs.h:3118 [inline] __do_sys_newlstat+0x8f/0x110 fs/stat.c:352 __se_sys_newlstat fs/stat.c:346 [inline] __x64_sys_newlstat+0x54/0x80 fs/stat.c:346 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 2a 60 09 <01> 87 01 8b 05 22 60 09 01 83 f8 01 0f 85 8a 00 00 00 b8 01 00 00 RSP: 002b:00007f45af14dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000006 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457569 RDX: 0000000000000000 RSI: 0000000020000340 RDI: 0000000020000000 RBP: 000000000072c0e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f45af14e6d4 R13: 00000000004c279a R14: 00000000004d3a38 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/982: #0: 0000000021c64c09 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5494: #0: 00000000761e70c6 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5585: #0: 000000006bb0ca89 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000008661630e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5586: #0: 0000000072e2cc33 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000007c6dd25a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5587: #0: 000000008341ca77 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000002634676a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5588: #0: 00000000f1da6228 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000011a63e6d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5589: #0: 00000000b87e0cf6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000386c9796 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5590: #0: 00000000d62b3a7a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000d0af6d03 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5591: #0: 00000000d898ea10 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000f00e249e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor0/9211: #0: 000000004fbb642f (&type->i_mutex_dir_key#9){++++}, at: inode_lock_shared include/linux/fs.h:748 [inline] #0: 000000004fbb642f (&type->i_mutex_dir_key#9){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1687 #1: 000000004817ad54 (&fi->mutex){+.+.}, at: fuse_lock_inode+0xba/0xf0 fs/fuse/inode.c:365 1 lock held by syz-executor0/9223: #0: 000000004fbb642f (&type->i_mutex_dir_key#9){++++}, at: inode_lock_shared include/linux/fs.h:748 [inline] #0: 000000004fbb642f (&type->i_mutex_dir_key#9){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1687 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 982 Comm: khungtaskd Not tainted 4.19.0+ #81 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/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:350 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57