INFO: task syz-executor1:15394 blocked for more than 140 seconds. Not tainted 4.20.0-rc6+ #374 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D19256 15394 26367 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 schedule+0xfe/0x460 kernel/sched/core.c:3516 xlog_grant_head_wait+0x26b/0xf50 fs/xfs/xfs_log.c:263 xlog_grant_head_check+0x4e7/0x560 fs/xfs/xfs_log.c:325 xfs_log_reserve+0x3b6/0xd50 fs/xfs/xfs_log.c:454 xfs_log_write_unmount_record+0x336/0xc30 fs/xfs/xfs_log.c:854 xfs_log_unmount_write fs/xfs/xfs_log.c:953 [inline] xfs_log_quiesce+0x55c/0x660 fs/xfs/xfs_log.c:1020 xfs_log_unmount+0x22/0xb0 fs/xfs/xfs_log.c:1034 xfs_log_mount_cancel+0x44/0x60 fs/xfs/xfs_log.c:816 xfs_mountfs+0x147f/0x1ef0 fs/xfs/xfs_mount.c:1064 xfs_fs_fill_super+0xe60/0x1720 fs/xfs/xfs_super.c:1745 mount_bdev+0x30c/0x3e0 fs/super.c:1158 xfs_fs_mount+0x34/0x40 fs/xfs/xfs_super.c:1819 mount_fs+0xae/0x31d fs/super.c:1261 vfs_kern_mount.part.35+0xdc/0x4f0 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2469 [inline] do_mount+0x581/0x31f0 fs/namespace.c:2801 ksys_mount+0x12d/0x140 fs/namespace.c:3017 __do_sys_mount fs/namespace.c:3031 [inline] __se_sys_mount fs/namespace.c:3028 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3028 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a0ca Code: 48 81 f9 00 00 40 00 77 09 48 8d 05 60 0d 00 00 ff e0 48 81 f9 00 00 80 00 77 09 48 8d 05 1e 0e 00 00 ff e0 48 81 f9 00 00 00 <01> 77 09 48 8d 05 dc 0e 00 00 ff e0 48 81 f9 00 00 00 02 77 09 48 RSP: 002b:00007f702e3e5a88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f702e3e5b30 RCX: 000000000045a0ca RDX: 00007f702e3e5ad0 RSI: 0000000020000100 RDI: 00007f702e3e5af0 RBP: 0000000020000100 R08: 00007f702e3e5b30 R09: 00007f702e3e5ad0 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000006 R13: 0000000000000000 R14: 00000000004d9c20 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1019: #0: 00000000c71d6ba1 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5873: #0: 00000000f43b425c (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5963: #0: 000000008fdffd1b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000004251956e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5964: #0: 00000000f97b514c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000006894f8da (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5965: #0: 000000002c8dfa75 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000000c44528e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5966: #0: 000000007e8465c0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000a4ede527 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5967: #0: 00000000fdbff118 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000054a4f50e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5968: #0: 00000000b530b1a9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000051b2bc96 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5969: #0: 000000005d2d7ef0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000a0cade37 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 1 lock held by syz-executor1/15394: #0: 00000000d77b9cd3 (&type->s_umount_key#47/1){+.+.}, at: alloc_super fs/super.c:226 [inline] #0: 00000000d77b9cd3 (&type->s_umount_key#47/1){+.+.}, at: sget_userns+0x2c5/0xed0 fs/super.c:519 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1019 Comm: khungtaskd Not tainted 4.20.0-rc6+ #374 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.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a 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:205 [inline] watchdog+0xb51/0x1060 kernel/hung_task.c:289 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 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:57