b_state=0x0000002b, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x0000002b, b_size=512 device loop0 blocksize: 4096 INFO: task syz-executor0:4463 blocked for more than 140 seconds. Not tainted 4.18.0-next-20180824+ #47 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D16904 4463 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x87c/0x1df0 kernel/sched/core.c:3473 __find_get_block_slow() failed. block=1, b_blocknr=8 schedule+0xfb/0x450 kernel/sched/core.c:3517 b_state=0x0000002b, b_size=512 device loop0 blocksize: 4096 wb_wait_for_completion+0x201/0x2e0 fs/fs-writeback.c:221 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x0000002b, b_size=512 device loop0 blocksize: 4096 __writeback_inodes_sb_nr+0x405/0x580 fs/fs-writeback.c:2333 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x0000002b, b_size=512 writeback_inodes_sb_nr fs/fs-writeback.c:2350 [inline] writeback_inodes_sb+0x27/0x30 fs/fs-writeback.c:2365 device loop0 blocksize: 4096 __sync_filesystem fs/sync.c:36 [inline] sync_filesystem+0x16f/0x330 fs/sync.c:64 generic_shutdown_super+0xdd/0x530 fs/super.c:441 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x0000002b, b_size=512 device loop0 blocksize: 4096 kill_block_super+0xa4/0x100 fs/super.c:1374 __find_get_block_slow() failed. block=1, b_blocknr=8 deactivate_locked_super+0x97/0x100 fs/super.c:328 deactivate_super+0x2bb/0x320 fs/super.c:359 b_state=0x0000002b, b_size=512 device loop0 blocksize: 4096 cleanup_mnt+0xbf/0x160 fs/namespace.c:1050 __find_get_block_slow() failed. block=1, b_blocknr=8 __cleanup_mnt+0x16/0x20 fs/namespace.c:1057 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 b_state=0x0000002b, b_size=512 device loop0 blocksize: 4096 tracehook_notify_resume include/linux/tracehook.h:193 [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 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x0000002b, b_size=512 device loop0 blocksize: 4096 entry_SYSCALL_64_after_hwframe+0x49/0xbe __find_get_block_slow() failed. block=1, b_blocknr=8 RIP: 0033:0x459a97 Code: Bad RIP value. b_state=0x0000002b, b_size=512 RSP: 002b:00007fff1d131468 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6 device loop0 blocksize: 4096 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000459a97 RDX: 0000000000408440 RSI: 0000000000000002 RDI: 00007fff1d131510 RBP: 0000000000001f70 R08: 0000000000000000 R09: 000000000000000c __find_get_block_slow() failed. block=1, b_blocknr=8 R10: 0000000000000005 R11: 0000000000000202 R12: 00007fff1d132570 R13: 0000000002784940 R14: 0000000000000000 R15: badc0ffeebadface b_state=0x0000002b, b_size=512 Showing all locks held in the system: device loop0 blocksize: 4096 1 lock held by khungtaskd/776: #0: 00000000cded4e74 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4436 2 locks held by rs:main Q:Reg/4324: #0: 000000003e6d1de9 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 0000000029628292 (sb_writers#6){.+.+}, at: file_start_write include/linux/fs.h:2799 [inline] #1: 0000000029628292 (sb_writers#6){.+.+}, at: vfs_write+0x42a/0x560 fs/read_write.c:548 1 lock held by rsyslogd/4326: #0: 0000000067a771a7 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 __find_get_block_slow() failed. block=1, b_blocknr=8 2 locks held by getty/4416: #0: 00000000d6f35839 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000a94b2fe1 ( b_state=0x0000002b, b_size=512 &ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4417: device loop0 blocksize: 4096 #0: 0000000087476645 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000006c834d39 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4418: #0: 000000004367b430 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 __find_get_block_slow() failed. block=1, b_blocknr=8 #1: 0000000086e5d0f7 b_state=0x0000002b, b_size=512 device loop0 blocksize: 4096 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4419: #0: 000000005723d0c7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000035a8218f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 __find_get_block_slow() failed. block=1, b_blocknr=8 2 locks held by getty/4420: #0: 000000006b92227d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000fc4d4adf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4421: #0: 000000003a79a8df ( b_state=0x0000002b, b_size=512 device loop0 blocksize: 4096 &tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 __find_get_block_slow() failed. block=1, b_blocknr=8 #1: 00000000b8c52883 ( b_state=0x0000002b, b_size=512 device loop0 blocksize: 4096 &ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 __find_get_block_slow() failed. block=1, b_blocknr=8 2 locks held by getty/4422: b_state=0x0000002b, b_size=512 #0: 000000003cf651f9 (&tty->ldisc_sem device loop0 blocksize: 4096 ){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000080460a36 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 1 lock held by syz-executor0/4463: #0: 00000000ad8f3931 (&fc->fs_type->s_umount_key#80){+.+.}, at: deactivate_super+0x2b3/0x320 fs/super.c:358 __find_get_block_slow() failed. block=1, b_blocknr=8 6 locks held by kworker/u4:2/12794: b_state=0x0000002b, b_size=512 2 locks held by kworker/0:3/1566: device loop0 blocksize: 4096 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 776 Comm: khungtaskd Not tainted 4.18.0-next-20180824+ #47 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 __find_get_block_slow() failed. block=1, b_blocknr=8 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 b_state=0x0000002b, b_size=512 nmi_cpu_backtrace.cold.3+0x48/0x88 lib/nmi_backtrace.c:101 device loop0 blocksize: 4096 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 __find_get_block_slow() failed. block=1, b_blocknr=8 trigger_all_cpu_backtrace include/linux/nmi.h:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0xb39/0x1040 kernel/hung_task.c:265 b_state=0x0000002b, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x0000002b, b_size=512 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 device loop0 blocksize: 4096 Sending NMI from CPU 1 to CPUs 0: __find_get_block_slow() failed. block=1, b_blocknr=8 NMI backtrace for cpu 0 CPU: 0 PID: 12794 Comm: kworker/u4:2 Not tainted 4.18.0-next-20180824+ #47 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:inb arch/x86/include/asm/io.h:333 [inline] RIP: 0010:io_serial_in+0x6b/0x90 drivers/tty/serial/8250/8250_port.c:449 Code: e1 00 00 00 49 8d 7c 24 38 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 d3 e3 80 3c 02 00 75 17 41 03 5c 24 38 89 da ec <5b> 0f b6 c0 41 5c 5d c3 e8 28 10 0c fe eb c2 e8 81 10 0c fe eb e2 RSP: 0018:ffff88018b32ddd0 EFLAGS: 00000006 RAX: dffffc0000000005 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: ffffffff83affe31 RDI: ffffffff8a30f6b8 RBP: ffff88018b32dde0 R08: fffffbfff1461ed1 R09: fffffbfff1461ed0 R10: fffffbfff1461ed0 R11: ffffffff8a30f683 R12: ffffffff8a30f680 R13: ffffffff8a30f8a0 R14: 0000000000000001 R15: ffffffff8a30f6c8 FS: 0000000000000000(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001b1457000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_port_in include/linux/serial_core.h:268 [inline] serial8250_console_write+0x2c5/0xb20 drivers/tty/serial/8250/8250_port.c:3252 univ8250_console_write+0x5f/0x70 drivers/tty/serial/8250/8250_core.c:590 call_console_drivers kernel/printk/printk.c:1726 [inline] console_unlock+0xace/0x10d0 kernel/printk/printk.c:2408 vprintk_emit+0x33a/0x910 kernel/printk/printk.c:1927 vprintk_default+0x28/0x30 kernel/printk/printk.c:1968 vprintk_func+0x7a/0x117 kernel/printk/printk_safe.c:398 printk+0xa7/0xcf kernel/printk/printk.c:2001 __find_get_block_slow fs/buffer.c:232 [inline] __find_get_block.cold.61+0x3a/0xff fs/buffer.c:1326 __getblk_slow fs/buffer.c:1059 [inline] __getblk_gfp+0x3dc/0xe00 fs/buffer.c:1352 __bread_gfp+0x2d/0x310 fs/buffer.c:1386 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+0xdc5/0x1380 fs/fs-writeback.c:1375 writeback_sb_inodes+0x71f/0x11a0 fs/fs-writeback.c:1580 wb_writeback+0x466/0xe80 fs/fs-writeback.c:1756 wb_do_writeback fs/fs-writeback.c:1901 [inline] wb_workfn+0x463/0x1610 fs/fs-writeback.c:1942 process_one_work+0xc73/0x1aa0 kernel/workqueue.c:2153 worker_thread+0x189/0x13c0 kernel/workqueue.c:2296 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415