__find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 INFO: task syz-executor6:4586 blocked for more than 120 seconds. device loop6 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 Not tainted 4.17.0-rc2+ #18 b_state=0x00000029, b_size=512 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor6 D device loop6 blocksize: 4096 21224 4586 1 0x00000004 Call Trace: __find_get_block_slow() failed. block=1, b_blocknr=8 context_switch kernel/sched/core.c:2848 [inline] __schedule+0x801/0x1e30 kernel/sched/core.c:3490 b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 schedule+0xef/0x430 kernel/sched/core.c:3549 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 wb_wait_for_completion+0x1ed/0x2d0 fs/fs-writeback.c:221 b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 __writeback_inodes_sb_nr+0x3e8/0x550 fs/fs-writeback.c:2340 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 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+0x15f/0x310 fs/sync.c:64 b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 generic_shutdown_super+0xd7/0x520 fs/super.c:429 b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 kill_block_super+0xa4/0x100 fs/super.c:1191 b_state=0x00000029, b_size=512 deactivate_locked_super+0x97/0x100 fs/super.c:316 device loop6 blocksize: 4096 deactivate_super+0x188/0x1b0 fs/super.c:347 __find_get_block_slow() failed. block=1, b_blocknr=8 cleanup_mnt+0xbf/0x160 fs/namespace.c:1174 __cleanup_mnt+0x16/0x20 fs/namespace.c:1181 b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 task_work_run+0x1e4/0x290 kernel/task_work.c:113 b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x2bd/0x310 arch/x86/entry/common.c:166 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:265 [inline] do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290 b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop6 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 loop6 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 RIP: 0033:0x457d97 RSP: 002b:00007ffebca6fff8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000457d97 __find_get_block_slow() failed. block=1, b_blocknr=8 RDX: 0000000001a41a13 RSI: 0000000000000002 RDI: 00007ffebca71160 RBP: 00007ffebca71160 R08: 0000000000000000 R09: 000000000000000b R10: 0000000000000005 R11: 0000000000000246 R12: 0000000001a41940 R13: 0000000000000000 R14: 000000000000033e R15: 000000000002f882 b_state=0x00000029, b_size=512 Showing all locks held in the system: device loop6 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 2 locks held by khungtaskd/892: b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 #0: (ptrval) (rcu_read_lock){....} b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 , at: check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] , at: watchdog+0x1ff/0xf60 kernel/hung_task.c:249 #1: __find_get_block_slow() failed. block=1, b_blocknr=8 (ptrval) (tasklist_lock){.+.+}, at: debug_show_all_locks+0xde/0x34a kernel/locking/lockdep.c:4470 1 lock held by rsyslogd/4415: b_state=0x00000029, b_size=512 #0: (ptrval) (&f->f_pos_lock device loop6 blocksize: 4096 ){+.+.}, at: __fdget_pos+0x1a9/0x1e0 fs/file.c:766 __find_get_block_slow() failed. block=1, b_blocknr=8 2 locks held by getty/4505: b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 #0: (ptrval) __find_get_block_slow() failed. block=1, b_blocknr=8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: b_state=0x00000029, b_size=512 (ptrval) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4506: device loop6 blocksize: 4096 #0: (ptrval) __find_get_block_slow() failed. block=1, b_blocknr=8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: b_state=0x00000029, b_size=512 (ptrval) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4507: device loop6 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 #0: (ptrval) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 #1: (ptrval) b_state=0x00000029, b_size=512 device loop6 blocksize: 4096 (&ldata->atomic_read_lock){+.+.} __find_get_block_slow() failed. block=1, b_blocknr=8 , at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4508: b_state=0x00000029, b_size=512 #0: (ptrval) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 device loop6 blocksize: 4096 #1: (ptrval) ( __find_get_block_slow() failed. block=1, b_blocknr=8 &ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4509: b_state=0x00000029, b_size=512 #0: (ptrval) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 device loop6 blocksize: 4096 #1: (ptrval) __find_get_block_slow() failed. block=1, b_blocknr=8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4510: b_state=0x00000029, b_size=512 #0: (ptrval) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: device loop6 blocksize: 4096 (ptrval) (&ldata->atomic_read_lock __find_get_block_slow() failed. block=1, b_blocknr=8 ){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4511: b_state=0x00000029, b_size=512 #0: (ptrval) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: device loop6 blocksize: 4096 (ptrval) (&ldata->atomic_read_lock __find_get_block_slow() failed. block=1, b_blocknr=8 ){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 1 lock held by syz-executor6/4586: b_state=0x00000029, b_size=512 #0: (ptrval) (&type->s_umount_key#46){++++}, at: deactivate_super+0x180/0x1b0 fs/super.c:346 device loop6 blocksize: 4096 ============================================= NMI backtrace for cpu 1 __find_get_block_slow() failed. block=1, b_blocknr=8 CPU: 1 PID: 892 Comm: khungtaskd Not tainted 4.17.0-rc2+ #18 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+0x1b9/0x294 lib/dump_stack.c:113 b_state=0x00000029, b_size=512 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 device loop6 blocksize: 4096 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline] check_hung_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0xc10/0xf60 kernel/hung_task.c:249 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 kthread+0x345/0x410 kernel/kthread.c:238 device loop6 blocksize: 4096 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 __find_get_block_slow() failed. block=1, b_blocknr=8 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 6 Comm: kworker/u4:0 Not tainted 4.17.0-rc2+ #18 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-7:6) RIP: 0010:print_time kernel/printk/printk.c:1221 [inline] RIP: 0010:print_prefix+0x38e/0x3f0 kernel/printk/printk.c:1246 RSP: 0018:ffff8801d9a95ef0 EFLAGS: 00000086 RAX: 000000000000000f RBX: 0000000000000001 RCX: ffffffff876ba8ac RDX: 0000000000000000 RSI: ffffffff876ba902 RDI: 0000000000000007 RBP: ffff8801d9a95f18 R08: ffff8801d9a88180 R09: fffffbfff11b09ec R10: fffffbfff11b09ec R11: ffffffff88d84f63 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000172 R15: 000000002b166d01 FS: 0000000000000000(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001cacec000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: msg_print_text+0x85/0x1c0 kernel/printk/printk.c:1269 console_unlock+0x4f5/0x1100 kernel/printk/printk.c:2369 vprintk_emit+0x6ad/0xdd0 kernel/printk/printk.c:1907 vprintk_default+0x28/0x30 kernel/printk/printk.c:1947 vprintk_func+0x7a/0xe7 kernel/printk/printk_safe.c:379 printk+0x9e/0xba kernel/printk/printk.c:1980 __find_get_block_slow fs/buffer.c:231 [inline] __find_get_block.cold.58+0x3a/0x103 fs/buffer.c:1287 __getblk_slow fs/buffer.c:1032 [inline] __getblk_gfp+0x2a1/0xaf0 fs/buffer.c:1313 __bread_gfp+0x2d/0x310 fs/buffer.c:1347 sb_bread include/linux/buffer_head.h:309 [inline] __fat_write_inode+0x33f/0xb40 fs/fat/inode.c:845 fat_write_inode+0x97/0x180 fs/fat/inode.c:894 write_inode fs/fs-writeback.c:1183 [inline] __writeback_single_inode+0xf18/0x15c0 fs/fs-writeback.c:1382 writeback_sb_inodes+0x6f0/0x11a0 fs/fs-writeback.c:1587 wb_writeback+0x463/0xf50 fs/fs-writeback.c:1763 wb_do_writeback fs/fs-writeback.c:1908 [inline] wb_workfn+0x46f/0x1770 fs/fs-writeback.c:1949 process_one_work+0xc1e/0x1b50 kernel/workqueue.c:2145 worker_thread+0x1cc/0x1440 kernel/workqueue.c:2279 kthread+0x345/0x410 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Code: 9b a0 2f b8 44 00 4c 89 f8 48 f7 e2 48 c1 ea 0b 49 89 d6 e8 a5 ea 18 00 4c 89 f1 31 f6 31 ff 48 c7 c2 e0 5a cb 87 e8 02 7d 0b 06 <48> 98 49 01 c4 e9 d7 fe ff ff 45 31 e4 e9 cf fe ff ff 45 31 e4