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-executor0:6118 blocked for more than 140 seconds. b_state=0x00000029, b_size=512 Not tainted 4.20.0-rc2+ #339 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 syz-executor0 D17752 6118 1 0x00000004 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 Call Trace: device loop0 blocksize: 4096 context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 __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 b_state=0x00000029, b_size=512 schedule+0xfe/0x460 kernel/sched/core.c:3516 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 b_state=0x00000029, b_size=512 wb_wait_for_completion+0x1f9/0x2d0 fs/fs-writeback.c:221 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 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 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 generic_shutdown_super+0xdd/0x530 fs/super.c:442 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 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 kill_block_super+0x9e/0x100 fs/super.c:1185 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 deactivate_locked_super+0x97/0x100 fs/super.c:329 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 deactivate_super+0x2bb/0x320 fs/super.c:360 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 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 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 cleanup_mnt+0xbf/0x160 fs/namespace.c:1098 __find_get_block_slow() failed. block=1, b_blocknr=8 __cleanup_mnt+0x16/0x20 fs/namespace.c:1105 b_state=0x00000029, b_size=512 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 device loop0 blocksize: 4096 __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:188 [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 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 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 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 entry_SYSCALL_64_after_hwframe+0x49/0xbe b_state=0x00000029, b_size=512 RIP: 0033:0x459fb7 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 Code: Bad RIP value. b_state=0x00000029, b_size=512 RSP: 002b:00007ffc8d6af838 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 device loop0 blocksize: 4096 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000459fb7 __find_get_block_slow() failed. block=1, b_blocknr=8 RDX: 0000000000402e70 RSI: 0000000000000002 RDI: 00007ffc8d6af8e0 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 RBP: 0000000000000156 R08: 0000000000000000 R09: 000000000000000a b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 R10: 0000000000000005 R11: 0000000000000206 R12: 00007ffc8d6b0970 b_state=0x00000029, b_size=512 R13: 0000000001ea5940 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 6 locks held by kworker/u4:2/44: b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 1 lock held by khungtaskd/1018: b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 00000000847d8a59 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 b_state=0x00000029, b_size=512 1 lock held by rsyslogd/5988: device loop0 blocksize: 4096 2 locks held by getty/6079: #0: 00000000742f2aa6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 __find_get_block_slow() failed. block=1, b_blocknr=8 #1: 00000000b6e8c108 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 b_state=0x00000029, b_size=512 2 locks held by getty/6080: device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 000000009639f59d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 b_state=0x00000029, b_size=512 #1: 0000000059f6ee63 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 device loop0 blocksize: 4096 2 locks held by getty/6081: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 000000003301eaa6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 b_state=0x00000029, b_size=512 #1: 000000004e130657 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 2 locks held by getty/6082: b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 000000005a66f3e3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 b_state=0x00000029, b_size=512 #1: 00000000f412de09 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 device loop0 blocksize: 4096 2 locks held by getty/6083: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 00000000655f7752 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 b_state=0x00000029, b_size=512 #1: 00000000173846a6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 2 locks held by getty/6084: b_state=0x00000029, b_size=512 #0: 0000000092d45216 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 device loop0 blocksize: 4096 #1: 0000000004792ed2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 __find_get_block_slow() failed. block=1, b_blocknr=8 2 locks held by getty/6085: b_state=0x00000029, b_size=512 #0: 00000000a2dd541b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 device loop0 blocksize: 4096 #1: 000000003c681e8b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 __find_get_block_slow() failed. block=1, b_blocknr=8 1 lock held by syz-executor0/6118: b_state=0x00000029, b_size=512 #0: 000000006b69892e (&type->s_umount_key#49){+.+.}, at: deactivate_super+0x2b3/0x320 fs/super.c:359 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 NMI backtrace for cpu 1 b_state=0x00000029, b_size=512 CPU: 1 PID: 1018 Comm: khungtaskd Not tainted 4.20.0-rc2+ #339 device loop0 blocksize: 4096 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 __find_get_block_slow() failed. block=1, b_blocknr=8 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a lib/nmi_backtrace.c:62 b_state=0x00000029, b_size=512 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:205 [inline] watchdog+0xb51/0x1060 kernel/hung_task.c:289 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 kthread+0x35a/0x440 kernel/kthread.c:246 __find_get_block_slow() failed. block=1, b_blocknr=8 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 b_state=0x00000029, b_size=512 Sending NMI from CPU 1 to CPUs 0: device loop0 blocksize: 4096 NMI backtrace for cpu 0 CPU: 0 PID: 44 Comm: kworker/u4:2 Not tainted 4.20.0-rc2+ #339 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:number+0x8c0/0xca0 lib/vsprintf.c:521 Code: e8 03 83 e1 07 0f b6 04 38 38 c8 7f 08 84 c0 0f 85 1c 03 00 00 41 88 14 24 41 83 ee 01 49 83 c4 01 49 83 ed 01 e8 b0 fb a8 f9 <31> ff 44 89 f6 e8 b6 fc a8 f9 41 83 fe ff 0f 85 75 ff ff ff 8b 85 RSP: 0018:ffff8881d95a5b98 EFLAGS: 00000093 RAX: ffff8881d959c400 RBX: 0000000000000000 RCX: ffffffff87d68f4a RDX: 0000000000000000 RSI: ffffffff87d68f40 RDI: 0000000000000005 RBP: ffff8881d95a5cb8 R08: ffff8881d959c400 R09: ffffed103b2b4bce R10: ffffed103b2b4bce R11: 0000000000000003 R12: 0000000000000005 R13: ffff8881d95a5c50 R14: 0000000000000000 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8881dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001be96c000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vsnprintf+0x13d0/0x1b60 lib/vsprintf.c:2362 snprintf+0xae/0xe0 lib/vsprintf.c:2429 print_time kernel/printk/printk.c:1226 [inline] print_prefix+0x38e/0x3f0 kernel/printk/printk.c:1251 msg_print_text+0x83/0x1d0 kernel/printk/printk.c:1274 console_unlock+0x4e6/0x1190 kernel/printk/printk.c:2388 vprintk_emit+0x391/0x990 kernel/printk/printk.c:1922 vprintk_default+0x28/0x30 kernel/printk/printk.c:1964 vprintk_func+0x7e/0x181 kernel/printk/printk_safe.c:398 printk+0xa7/0xcf kernel/printk/printk.c:1997 __find_get_block_slow fs/buffer.c:237 [inline] __find_get_block.cold.57+0xd8/0xff fs/buffer.c:1294 __getblk_slow fs/buffer.c:1039 [inline] __getblk_gfp+0x2b3/0xd50 fs/buffer.c:1320 __bread_gfp+0x2d/0x310 fs/buffer.c:1354 sb_bread include/linux/buffer_head.h:307 [inline] __fat_write_inode+0x347/0xb60 fs/fat/inode.c:859 fat_write_inode+0x97/0x180 fs/fat/inode.c:908 write_inode fs/fs-writeback.c:1176 [inline] __writeback_single_inode+0xf56/0x1660 fs/fs-writeback.c:1375 writeback_sb_inodes+0x71f/0x1210 fs/fs-writeback.c:1580 wb_writeback+0x48c/0xfc0 fs/fs-writeback.c:1756 wb_do_writeback fs/fs-writeback.c:1901 [inline] wb_workfn+0x495/0x1790 fs/fs-writeback.c:1942 process_one_work+0xc90/0x1c40 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