kworker/u4:1(21): getblk(): executed=9 bh_count=0 bh_state=0 kworker/u4:1(21): getblk(): executed=9 bh_count=0 bh_state=0 kworker/u4:1(21): getblk(): executed=9 bh_count=0 bh_state=0 kworker/u4:1(21): getblk(): executed=9 bh_count=0 bh_state=0 kworker/u4:1(21): getblk(): executed=9 bh_count=0 bh_state=0 INFO: task syz-executor0:19086 blocked for more than 140 seconds. Not tainted 4.20.0-rc1-next-20181105+ #105 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D17952 19086 1 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 wb_wait_for_completion+0x1f9/0x2d0 fs/fs-writeback.c:221 __writeback_inodes_sb_nr+0x405/0x580 fs/fs-writeback.c:2333 writeback_inodes_sb_nr fs/fs-writeback.c:2350 [inline] writeback_inodes_sb+0x27/0x30 fs/fs-writeback.c:2365 __sync_filesystem fs/sync.c:36 [inline] sync_filesystem+0x16f/0x330 fs/sync.c:64 generic_shutdown_super+0xdd/0x530 fs/super.c:441 kill_block_super+0x9e/0x100 fs/super.c:1383 deactivate_locked_super+0x97/0x100 fs/super.c:328 deactivate_super+0x2bb/0x320 fs/super.c:359 cleanup_mnt+0xbf/0x160 fs/namespace.c:1049 __cleanup_mnt+0x16/0x20 fs/namespace.c:1056 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x318/0x380 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: 0033:0x459fb7 Code: Bad RIP value. RSP: 002b:00007ffc1fa23ea8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000459fb7 RDX: 0000000000402e70 RSI: 0000000000000002 RDI: 00007ffc1fa23f50 RBP: 00000000000001ef R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000005 R11: 0000000000000202 R12: 00007ffc1fa24fe0 R13: 0000000002178940 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 3 locks held by kworker/u4:1/21: 1 lock held by khungtaskd/1008: #0: 0000000039ab7285 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5587: #0: 00000000e332387e (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5677: #0: 0000000011306e15 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000d8855b45 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5678: #0: 00000000505896c3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000b0cfa55b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5679: #0: 000000005216b9f4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000961ee07c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5680: #0: 000000000e26b359 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000bf63f5db (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5681: #0: 000000002793a575 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000f474a425 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5682: #0: 000000000ec38fa0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000002211fc56 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5683: #0: 0000000038a5331d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e06e882b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 1 lock held by syz-executor0/19086: #0: 00000000712ae8ec (&fc->fs_type->s_umount_key#77){++++}, at: deactivate_super+0x2b3/0x320 fs/super.c:358 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1008 Comm: khungtaskd Not tainted 4.20.0-rc1-next-20181105+ #105 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:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xb4c/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: INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.215 msecs NMI backtrace for cpu 1 CPU: 1 PID: 21 Comm: kworker/u4:1 Not tainted 4.20.0-rc1-next-20181105+ #105 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:debug_lockdep_rcu_enabled.part.3+0xf/0x60 kernel/rcu/update.c:246 Code: 59 89 e8 b4 82 00 00 ba 02 00 00 00 eb dc 0f 0b b8 ff ff ff ff 5d c3 0f 1f 40 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 e5 53 <65> 48 8b 1c 25 40 ee 01 00 48 8d bb 7c 08 00 00 48 89 fa 48 c1 ea RSP: 0018:ffff8801d9456058 EFLAGS: 00000202 RAX: dffffc0000000000 RBX: ffff8801d9448580 RCX: ffffffff819d5c5f RDX: 0000000000000000 RSI: 00000000000001e1 RDI: ffffffff8a1544b4 RBP: ffff8801d9456060 R08: ffff8801d9448580 R09: ffffed003b5e5b67 R10: 0000000000000003 R11: ffff8801daf2db3b R12: 1ffff1003b28ac11 R13: 0000000000000000 R14: ffffffff8831cd60 R15: 00000000000001e1 FS: 0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001d5db8000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_lockdep_rcu_enabled+0x77/0x90 kernel/rcu/update.c:248 ___might_sleep+0x6e/0x340 kernel/sched/core.c:6107 __might_sleep+0x95/0x190 kernel/sched/core.c:6095 lock_page include/linux/pagemap.h:481 [inline] pagecache_get_page+0x7f6/0xf00 mm/filemap.c:1531 find_or_create_page include/linux/pagemap.h:322 [inline] grow_dev_page fs/buffer.c:947 [inline] grow_buffers fs/buffer.c:1029 [inline] __getblk_slow fs/buffer.c:1062 [inline] __getblk_gfp+0x4ca/0x1030 fs/buffer.c:1351 __bread_gfp+0x2d/0x310 fs/buffer.c:1385 sb_bread include/linux/buffer_head.h:307 [inline] __fat_write_inode+0x347/0xb60 fs/fat/inode.c:860 fat_write_inode+0x97/0x180 fs/fat/inode.c:909 write_inode fs/fs-writeback.c:1176 [inline] __writeback_single_inode+0xf4a/0x1650 fs/fs-writeback.c:1375 writeback_sb_inodes+0x71f/0x1210 fs/fs-writeback.c:1580 wb_writeback+0x487/0xfb0 fs/fs-writeback.c:1756 wb_do_writeback fs/fs-writeback.c:1901 [inline] wb_workfn+0x490/0x1780 fs/fs-writeback.c:1942 process_one_work+0xc8b/0x1c40 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352