INFO: task syz-executor0:4548 blocked for more than 120 seconds. Not tainted 4.18.0-rc2+ #116 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D18104 4548 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x87c/0x1ed0 kernel/sched/core.c:3504 schedule+0xfb/0x450 kernel/sched/core.c:3548 wb_wait_for_completion+0x201/0x2e0 fs/fs-writeback.c:221 __writeback_inodes_sb_nr+0x405/0x580 fs/fs-writeback.c:2340 writeback_inodes_sb_nr fs/fs-writeback.c:2357 [inline] writeback_inodes_sb+0x27/0x30 fs/fs-writeback.c:2372 __sync_filesystem fs/sync.c:36 [inline] sync_filesystem+0x16f/0x330 fs/sync.c:64 generic_shutdown_super+0xdd/0x530 fs/super.c:439 kill_block_super+0xa4/0x100 fs/super.c:1201 deactivate_locked_super+0x97/0x100 fs/super.c:326 deactivate_super+0x193/0x1c0 fs/super.c:357 cleanup_mnt+0xbf/0x160 fs/namespace.c:1174 __cleanup_mnt+0x16/0x20 fs/namespace.c:1181 task_work_run+0x1ec/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:192 [inline] exit_to_usermode_loop+0x313/0x370 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4584a7 Code: Bad RIP value. RSP: 002b:00007ffe0ec98fe8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000004584a7 RDX: 0000000001a199f3 RSI: 0000000000000002 RDI: 00007ffe0ec9a150 RBP: 00007ffe0ec9a150 R08: 0000000000000000 R09: 000000000000000b R10: 0000000000000005 R11: 0000000000000246 R12: 0000000001a19940 R13: 0000000000000000 R14: 00007ffe0ec9b830 R15: 0000000000701140 Showing all locks held in the system: 2 locks held by kworker/u4:4/301: 1 lock held by khungtaskd/900: #0: 00000000d341e3d5 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 2 locks held by rs:main Q:Reg/4407: #0: 0000000066926182 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1805 [inline] #0: 0000000066926182 (&rq->lock){-.-.}, at: __schedule+0x24d/0x1ed0 kernel/sched/core.c:3442 #1: 00000000d1a6bc3c (sb_writers#6){.+.+}, at: file_start_write include/linux/fs.h:2739 [inline] #1: 00000000d1a6bc3c (sb_writers#6){.+.+}, at: vfs_write+0x452/0x560 fs/read_write.c:548 1 lock held by rsyslogd/4409: #0: 00000000751fdf51 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/4499: #0: 00000000d45aa8d2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000a803d4b9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2131 2 locks held by getty/4500: #0: 0000000053484b7d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000fd8199e4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2131 2 locks held by getty/4501: #0: 00000000776068ee (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000943edc4c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2131 2 locks held by getty/4502: #0: 0000000005f6aeed (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000030f4e19a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2131 2 locks held by getty/4503: #0: 000000008742d5fc (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000005b589ee6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2131 2 locks held by getty/4504: #0: 00000000310a76ab (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000000bbee0d1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2131 2 locks held by getty/4505: #0: 0000000095c03979 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000e205f1db (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2131 1 lock held by syz-executor0/4548: #0: 00000000b7746624 (&type->s_umount_key#66){++++}, at: deactivate_super+0x18b/0x1c0 fs/super.c:356 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 900 Comm: khungtaskd Not tainted 4.18.0-rc2+ #116 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+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 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:138 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline] watchdog+0x9c4/0xf80 kernel/hung_task.c:252 kthread+0x345/0x410 kernel/kthread.c:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4407 Comm: rs:main Q:Reg Not tainted 4.18.0-rc2+ #116 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__ext4_get_inode_loc+0x2bf/0x14c0 fs/ext4/inode.c:4512 Code: 24 ff 48 ba 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c 11 00 0f 85 d0 0f 00 00 49 8d 7f 10 31 d2 48 89 f9 49 f7 75 20 <48> ba 00 00 00 00 00 fc ff df 48 c1 e9 03 0f b6 14 11 84 d2 74 09 RSP: 0018:ffff8801af027168 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff8801cc256880 RCX: ffff8801af0273b8 RDX: 000000000000004f RSI: ffffffff820b0abe RDI: ffff8801af0273b8 RBP: ffff8801af0272b8 R08: ffff8801b0ab0240 R09: ffffed003b5c46d6 R10: ffffed003b5c46d6 R11: ffff8801dae236b3 R12: 0000000000004050 R13: ffff8801cc2588c0 R14: ffff8801bf8a1630 R15: ffff8801af0273a8 FS: 00007f050e5d1700(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000001c82000 CR3: 00000001b0f9b000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ext4_get_inode_loc fs/ext4/inode.c:4639 [inline] ext4_reserve_inode_write+0xf8/0x260 fs/ext4/inode.c:5791 ext4_mark_inode_dirty+0x182/0xb50 fs/ext4/inode.c:5943 ext4_dirty_inode+0x97/0xc0 fs/ext4/inode.c:5982 __mark_inode_dirty+0x825/0x1550 fs/fs-writeback.c:2129 generic_update_time+0x26a/0x450 fs/inode.c:1643 update_time fs/inode.c:1659 [inline] file_update_time+0x390/0x640 fs/inode.c:1870 __generic_file_write_iter+0x1dc/0x630 mm/filemap.c:3214 ext4_file_write_iter+0x390/0x1430 fs/ext4/file.c:266 call_write_iter include/linux/fs.h:1795 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6c6/0x9f0 fs/read_write.c:487 vfs_write+0x1f8/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f051002f19d Code: d1 20 00 00 75 10 b8 01 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 be fa ff ff 48 89 04 24 b8 01 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 07 fb ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007f050e5cff90 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000400 RCX: 00007f051002f19d RDX: 0000000000000400 RSI: 0000000001c72a90 RDI: 0000000000000005 RBP: 0000000001c72a90 R08: 0000000001ccabd0 R09: 30373320205b203a R10: 5d3335313432332e R11: 0000000000000293 R12: 0000000000000000 R13: 00007f050e5d0410 R14: 0000000001ccabd0 R15: 0000000001c72890 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.026 msecs