INFO: task syz-executor.0:14135 blocked for more than 140 seconds. Not tainted 4.19.56 #28 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29256 14135 7796 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x80d/0x1c70 kernel/sched/core.c:3474 schedule+0x92/0x1c0 kernel/sched/core.c:3518 request_wait_answer+0x42f/0x7c0 fs/fuse/dev.c:485 __fuse_request_send+0x128/0x1d0 fs/fuse/dev.c:505 fuse_request_send+0x60/0xa0 fs/fuse/dev.c:518 fuse_simple_request+0x2f6/0x720 fs/fuse/dev.c:576 fuse_lookup_name+0x275/0x670 fs/fuse/dir.c:323 fuse_lookup+0xeb/0x3e0 fs/fuse/dir.c:361 __lookup_hash+0x11d/0x190 fs/namei.c:1546 filename_create+0x1a7/0x4f0 fs/namei.c:3636 user_path_create fs/namei.c:3693 [inline] do_mknodat fs/namei.c:3754 [inline] do_mknodat+0x1a4/0x480 fs/namei.c:3742 __do_sys_mknod fs/namei.c:3794 [inline] __se_sys_mknod fs/namei.c:3792 [inline] __x64_sys_mknod+0x7b/0xb0 fs/namei.c:3792 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4597c9 Code: Bad RIP value. RSP: 002b:00007f998cae5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004597c9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200001c0 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f998cae66d4 R13: 00000000004c5af8 R14: 00000000004da220 R15: 00000000ffffffff Showing all locks held in the system: 3 locks held by kworker/u4:1/23: #0: 000000001194db0a (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1821 [inline] #0: 000000001194db0a (&rq->lock){-.-.}, at: __schedule+0x1f8/0x1c70 kernel/sched/core.c:3412 #1: 000000001694fbc0 (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:5995 #2: 00000000255d82d2 (&base->lock){-.-.}, at: lock_timer_base+0x56/0x1b0 kernel/time/timer.c:938 1 lock held by khungtaskd/1032: #0: 000000001694fbc0 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4435 2 locks held by rsyslogd/7632: #0: 000000004ec75c20 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 #1: 000000007a8cdbe8 (log_wait.lock){-.-.}, at: __debug_check_no_obj_freed lib/debugobjects.c:776 [inline] #1: 000000007a8cdbe8 (log_wait.lock){-.-.}, at: debug_check_no_obj_freed+0xbe/0x464 lib/debugobjects.c:817 2 locks held by getty/7754: #0: 00000000add2b891 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 0000000029e844e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7755: #0: 00000000685532b8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 0000000015eefcf4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7756: #0: 000000005ef50443 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 0000000045596023 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7757: #0: 000000000e08349f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 0000000044d56c95 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7758: #0: 000000003657a11d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000d2fa97e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7759: #0: 0000000021679071 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000c73d7ce0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7760: #0: 00000000c34bc333 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 000000008d575673 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 3 locks held by syz-executor.0/14135: #0: 000000006710d26f (sb_writers#17){.+.+}, at: sb_start_write include/linux/fs.h:1578 [inline] #0: 000000006710d26f (sb_writers#17){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360 #1: 000000005affd3c9 (&type->i_mutex_dir_key#8/1){+.+.}, at: inode_lock_nested include/linux/fs.h:782 [inline] #1: 000000005affd3c9 (&type->i_mutex_dir_key#8/1){+.+.}, at: filename_create+0x17c/0x4f0 fs/namei.c:3635 #2: 000000003abeb6e5 (&fi->mutex){+.+.}, at: fuse_lock_inode+0xba/0xf0 fs/fuse/inode.c:365 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1032 Comm: khungtaskd Not tainted 4.19.56 #28 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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 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+0x9df/0xee0 kernel/hung_task.c:287 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 2278 Comm: kworker/u4:4 Not tainted 4.19.56 #28 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: (null) (flush-8:0) RIP: 0010:sched_submit_work kernel/sched/core.c:3501 [inline] RIP: 0010:schedule+0x0/0x1c0 kernel/sched/core.c:3515 Code: 73 f2 ff ff e8 11 0f b3 fa e9 da f2 ff ff e8 e7 0e b3 fa e9 31 f3 ff ff e8 fd f6 b2 fa 48 c7 c7 40 09 4b 87 e8 f2 83 50 fa 90 <48> b8 00 00 00 00 00 fc ff df 55 48 89 e5 41 54 53 65 48 8b 1c 25 RSP: 0018:ffff8880a1e07e50 EFLAGS: 00000286 RAX: 0000000080000000 RBX: ffff8880a1df2440 RCX: 0000000000000000 RDX: 0000000000000004 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffff8880a1e07f00 R08: ffff8880a1df2440 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a2713508 R13: ffff8880a573e200 R14: ffff88812c3ee940 R15: ffff8880a2713500 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000130 CR3: 0000000092599000 CR4: 00000000001406f0 Call Trace: kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415