INFO: task syz-executor2:626 blocked for more than 140 seconds. Not tainted 5.0.0-rc3-next-20190125 #20 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D22424 626 14127 0x00000004 Call Trace: context_switch kernel/sched/core.c:2847 [inline] __schedule+0x897/0x1e60 kernel/sched/core.c:3488 schedule+0xfe/0x350 kernel/sched/core.c:3532 xlog_grant_head_wait+0x24e/0x1120 fs/xfs/xfs_log.c:263 xlog_grant_head_check+0x4cb/0x540 fs/xfs/xfs_log.c:325 xfs_log_reserve+0x399/0xd40 fs/xfs/xfs_log.c:454 xfs_log_write_unmount_record+0x311/0xc00 fs/xfs/xfs_log.c:854 xfs_log_unmount_write fs/xfs/xfs_log.c:953 [inline] xfs_log_quiesce+0x579/0x670 fs/xfs/xfs_log.c:1020 xfs_log_unmount+0x22/0xb0 fs/xfs/xfs_log.c:1034 xfs_log_mount_cancel+0x47/0x60 fs/xfs/xfs_log.c:816 xfs_mountfs+0x1657/0x2190 fs/xfs/xfs_mount.c:1068 xfs_fs_fill_super+0xea3/0x1790 fs/xfs/xfs_super.c:1746 mount_bdev+0x307/0x3c0 fs/super.c:1346 xfs_fs_mount+0x35/0x40 fs/xfs/xfs_super.c:1820 legacy_get_tree+0xf2/0x200 fs/fs_context.c:590 vfs_get_tree+0x123/0x450 fs/super.c:1481 do_new_mount fs/namespace.c:2610 [inline] do_mount+0x1622/0x2fa0 fs/namespace.c:2932 ksys_mount+0xdb/0x150 fs/namespace.c:3148 __do_sys_mount fs/namespace.c:3162 [inline] __se_sys_mount fs/namespace.c:3159 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3159 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45ab0a Code: Bad RIP value. RSP: 002b:00007fce9f7fda88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fce9f7fdb30 RCX: 000000000045ab0a RDX: 00007fce9f7fdad0 RSI: 0000000020000100 RDI: 00007fce9f7fdaf0 RBP: 0000000020000100 R08: 00007fce9f7fdb30 R09: 00007fce9f7fdad0 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000003 R13: 0000000000000000 R14: 00000000004dbdf0 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1038: #0: 00000000ff43b21e (rcu_read_lock){....}, at: debug_show_all_locks+0xc6/0x41d kernel/locking/lockdep.c:4393 1 lock held by rsyslogd/7849: #0: 000000001e27f306 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1b3/0x1f0 fs/file.c:796 2 locks held by getty/7939: #0: 00000000c10ffca5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008ea65198 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2156 2 locks held by getty/7940: #0: 000000004df9c14e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000f52687eb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2156 2 locks held by getty/7941: #0: 00000000899ce2d9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000003327ee7b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2156 2 locks held by getty/7942: #0: 00000000a79a9279 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000c5dabf63 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2156 2 locks held by getty/7943: #0: 00000000643595a3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000014ff27c5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2156 2 locks held by getty/7944: #0: 0000000036dac4d1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008b56a90a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2156 2 locks held by getty/7945: #0: 00000000a362b8aa (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000002df79b24 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2156 1 lock held by syz-executor2/626: #0: 00000000a3a5aa8f (&type->s_umount_key#56/1){+.+.}, at: alloc_super+0x1ff/0xa10 fs/super.c:228 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1038 Comm: khungtaskd Not tainted 5.0.0-rc3-next-20190125 #20 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:247 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: