device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 INFO: task syz-executor0:4502 blocked for more than 140 seconds. b_state=0x00000029, b_size=512 Not tainted 4.18.0-next-20180821+ #44 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D21184 4502 1 0x00000004 device loop0 blocksize: 4096 Call Trace: __find_get_block_slow() failed. block=1, b_blocknr=8 context_switch kernel/sched/core.c:2825 [inline] __schedule+0x87c/0x1df0 kernel/sched/core.c:3473 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 schedule+0xfb/0x450 kernel/sched/core.c:3517 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 wb_wait_for_completion+0x201/0x2e0 fs/fs-writeback.c:221 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, 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=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 writeback_inodes_sb_nr fs/fs-writeback.c:2350 [inline] writeback_inodes_sb+0x27/0x30 fs/fs-writeback.c:2365 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __sync_filesystem fs/sync.c:36 [inline] sync_filesystem+0x16f/0x330 fs/sync.c:64 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 generic_shutdown_super+0xdd/0x530 fs/super.c:441 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, 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=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 cleanup_mnt+0xbf/0x160 fs/namespace.c:1050 __cleanup_mnt+0x16/0x20 fs/namespace.c:1057 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, 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 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 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 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 entry_SYSCALL_64_after_hwframe+0x49/0xbe b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 RIP: 0033:0x459a97 Code: Bad RIP value. __find_get_block_slow() failed. block=1, b_blocknr=8 RSP: 002b:00007ffefd7ea9f8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000459a97 RDX: 0000000000408440 RSI: 0000000000000002 RDI: 00007ffefd7eaaa0 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 RBP: 00000000000002b8 R08: 0000000000000000 R09: 000000000000000b R10: 0000000000000005 R11: 0000000000000206 R12: 00007ffefd7ebb00 __find_get_block_slow() failed. block=1, b_blocknr=8 R13: 0000000002012940 R14: 0000000000000000 R15: badc0ffeebadface Showing all locks held in the system: b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 3 locks held by kworker/u4:4/765: 1 lock held by khungtaskd/772: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 0000000045a5818d (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4436 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 1 lock held by rsyslogd/4364: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 00000000edd6f58f (&f->f_pos_lock){+.+.} b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 , at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/4454: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 00000000ee6d8f3b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 #1: 000000005cc90d9f ( __find_get_block_slow() failed. block=1, b_blocknr=8 &ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4455: b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 #0: 00000000a06b658b ( __find_get_block_slow() failed. block=1, b_blocknr=8 &tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 000000005066b307 (&ldata->atomic_read_lock __find_get_block_slow() failed. block=1, b_blocknr=8 ){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4456: #0: b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 0000000018681a5e (&tty->ldisc_sem __find_get_block_slow() failed. block=1, b_blocknr=8 ){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000d444fa52 b_state=0x00000029, b_size=512 (&ldata->atomic_read_lock){+.+.} device loop0 blocksize: 4096 , at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4457: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 00000000fedec6d3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 #1: 00000000ee0d033b ( __find_get_block_slow() failed. block=1, b_blocknr=8 &ldata->atomic_read_lock){+.+.} b_state=0x00000029, b_size=512 , at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4458: device loop0 blocksize: 4096 #0: 00000000cd393c45 __find_get_block_slow() failed. block=1, b_blocknr=8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: b_state=0x00000029, b_size=512 00000000374fbcc0 (&ldata->atomic_read_lock device loop0 blocksize: 4096 ){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4459: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 000000005a6a8669 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 0000000099493c31 ( __find_get_block_slow() failed. block=1, b_blocknr=8 &ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4460: b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 #0: 00000000d9563a14 ( __find_get_block_slow() failed. block=1, b_blocknr=8 &tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: b_state=0x00000029, b_size=512 000000005a055404 ( device loop0 blocksize: 4096 &ldata->atomic_read_lock){+.+.} __find_get_block_slow() failed. block=1, b_blocknr=8 , at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 1 lock held by syz-executor0/4502: #0: b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 00000000c3e57a04 (&fc->fs_type->s_umount_key#76){+.+.}, at: deactivate_super+0x2b3/0x320 fs/super.c:358 __find_get_block_slow() failed. block=1, b_blocknr=8 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 772 Comm: khungtaskd Not tainted 4.18.0-next-20180821+ #44 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 b_state=0x00000029, b_size=512 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 device loop0 blocksize: 4096 nmi_cpu_backtrace.cold.3+0x48/0x88 lib/nmi_backtrace.c:101 __find_get_block_slow() failed. block=1, b_blocknr=8 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:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0xb39/0x1040 kernel/hung_task.c:265 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 kthread+0x35a/0x420 kernel/kthread.c:246 b_state=0x00000029, b_size=512 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: device loop0 blocksize: 4096 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.420 msecs NMI backtrace for cpu 1 CPU: 1 PID: 765 Comm: kworker/u4:4 Not tainted 4.18.0-next-20180821+ #44 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:write_comp_data+0x0/0x70 Code: fd ff ff 48 8b bd d0 fe ff ff e8 7b 2f 3f 00 e9 ad fc ff ff 4c 89 ef e8 ce 2e 3f 00 e9 76 fc ff ff e8 c4 c6 ca ff 90 90 90 90 <55> 65 4c 8b 04 25 40 ee 01 00 65 8b 05 4f 27 85 7e 48 89 e5 a9 00 RSP: 0018:ffff8801db1078e8 EFLAGS: 00000006 RAX: dffffc0000000000 RBX: 00000000000000c0 RCX: ffffffff83612d77 RDX: 0000000200000000 RSI: 0000000000000000 RDI: 0000000000000007 RBP: ffff8801db1078f0 R08: ffff8801d87d6440 R09: ffffed003b6246e8 R10: ffffed003b6246e8 R11: ffff8801db123743 R12: 0000000200000000 R13: 0000000000000100 R14: ffff8801db123798 R15: ffff8801db1237b0 FS: 0000000000000000(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9dcb133140 CR3: 00000001c59c3000 CR4: 00000000001406e0 Call Trace: _find_next_bit lib/find_bit.c:52 [inline] find_next_bit+0x77/0x130 lib/find_bit.c:74 next_pending_bucket kernel/time/timer.c:1406 [inline] __next_timer_interrupt+0x120/0x1a0 kernel/time/timer.c:1426 collect_expired_timers kernel/time/timer.c:1599 [inline] __run_timers+0x281/0xc60 kernel/time/timer.c:1678 run_timer_softirq+0x1d/0x40 kernel/time/timer.c:1695 __do_softirq+0x2eb/0xa74 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x1d6/0x210 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x18e/0x6a0 arch/x86/kernel/apic/apic.c:1056 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:867 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:783 [inline] RIP: 0010:console_trylock_spinning kernel/printk/printk.c:1686 [inline] RIP: 0010:vprintk_emit+0x7f9/0x910 kernel/printk/printk.c:1926 Code: 00 00 00 00 fc ff df 41 80 3c 04 00 0f 85 d3 00 00 00 48 83 3d 3f 3a 8e 06 00 74 2d e8 70 45 19 00 48 8b bd 90 fe ff ff 57 9d <0f> 1f 44 00 00 e9 68 fe ff ff e8 58 45 19 00 0f 0b e8 51 45 19 00 RSP: 0018:ffff8801d85e60c0 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffff8801d87d6440 RBX: 1ffff1003b0bcc1e RCX: 1ffff1003b0fad9e RDX: 0000000000000000 RSI: ffffffff81638170 RDI: 0000000000000293 RBP: ffff8801d85e6238 R08: ffff8801d87d6c80 R09: 0000000000000006 R10: ffff8801d87d6440 R11: 0000000000000000 R12: 1ffffffff0fe3775 R13: 0000000000000200 R14: ffff8801d85e6210 R15: 0000000000000000 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:238 [inline] __find_get_block.cold.61+0xd8/0xff 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:864 fat_write_inode+0x97/0x180 fs/fat/inode.c:913 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