INFO: task syz-executor4:27882 blocked for more than 140 seconds. Not tainted 5.0.0-rc4-next-20190201 #25 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D26080 27882 7962 0x00000004 Call Trace: context_switch kernel/sched/core.c:2847 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3488 schedule+0x92/0x180 kernel/sched/core.c:3532 xlog_grant_head_wait+0x14e/0xd00 fs/xfs/xfs_log.c:263 xlog_grant_head_check+0x436/0x4a0 fs/xfs/xfs_log.c:325 xfs_log_reserve+0x371/0xae0 fs/xfs/xfs_log.c:454 xfs_log_write_unmount_record fs/xfs/xfs_log.c:854 [inline] xfs_log_unmount_write fs/xfs/xfs_log.c:953 [inline] xfs_log_quiesce+0x40d/0xcf0 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+0x1563/0x1fb0 fs/xfs/xfs_mount.c:1068 xfs_fs_fill_super+0xd0a/0x14f0 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:2612 [inline] do_mount+0x1436/0x2c40 fs/namespace.c:2934 ksys_mount+0xdb/0x150 fs/namespace.c:3150 __do_sys_mount fs/namespace.c:3164 [inline] __se_sys_mount fs/namespace.c:3161 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3161 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a8aa Code: 00 00 48 29 f0 48 3d f8 82 00 00 76 7d 48 81 ec 08 80 00 00 48 89 ac 24 00 80 00 00 48 8d ac 24 00 80 00 00 48 8b 59 20 48 85 75 67 48 8b b4 24 20 80 00 00 8b 8c 24 28 80 00 00 48 89 e7 f3 RSP: 002b:00007f3f399c8a88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f3f399c8b30 RCX: 000000000045a8aa RDX: 00007f3f399c8ad0 RSI: 0000000020000100 RDI: 00007f3f399c8af0 RBP: 0000000020000100 R08: 00007f3f399c8b30 R09: 00007f3f399c8ad0 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000004 R13: 0000000000000000 R14: 00000000004dbb70 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1040: #0: 0000000085652b7c (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4374 2 locks held by rsyslogd/7823: #0: 0000000020c7f763 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:796 #1: 0000000085652b7c (rcu_read_lock){....}, at: is_bpf_text_address+0x0/0x170 kernel/bpf/core.c:668 2 locks held by getty/7913: #0: 000000006712afc2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000e9b5aef5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7914: #0: 0000000022cc7f35 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000e3ceea3a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7915: #0: 00000000b895f75b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000009029f23b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7916: #0: 00000000ef311fda (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000d7da0e5b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7917: #0: 000000005393d109 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008a90f8e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7918: #0: 00000000b252d0c5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000021ea1ee6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7919: #0: 0000000048a58b50 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000ba990b23 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by syz-executor0/10454: #0: 000000009ceb3ae1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000096b5921d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 1 lock held by syz-executor4/27882: #0: 00000000f37d2cd4 (&type->s_umount_key#50/1){+.+.}, at: alloc_super+0x158/0x890 fs/super.c:228 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1040 Comm: khungtaskd Not tainted 5.0.0-rc4-next-20190201 #25 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+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:204 [inline] watchdog+0x9df/0xee0 kernel/hung_task.c:288 kthread+0x357/0x430 kernel/kthread.c:247 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: