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-executor0:4578 blocked for more than 120 seconds. b_state=0x00000029, b_size=512 Not tainted 4.17.0-rc5+ #52 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. device loop0 blocksize: 4096 syz-executor0 D __find_get_block_slow() failed. block=1, b_blocknr=8 21192 4578 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2859 [inline] __schedule+0x801/0x1e30 kernel/sched/core.c:3501 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+0xef/0x430 kernel/sched/core.c:3545 device loop0 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 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+0x3e8/0x550 fs/fs-writeback.c:2340 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:2357 [inline] writeback_inodes_sb+0x27/0x30 fs/fs-writeback.c:2372 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 __sync_filesystem fs/sync.c:36 [inline] sync_filesystem+0x15f/0x310 fs/sync.c:64 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 generic_shutdown_super+0xd7/0x520 fs/super.c:429 __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 kill_block_super+0xa4/0x100 fs/super.c:1191 deactivate_locked_super+0x97/0x100 fs/super.c:316 deactivate_super+0x188/0x1b0 fs/super.c:347 device loop0 blocksize: 4096 cleanup_mnt+0xbf/0x160 fs/namespace.c:1174 __find_get_block_slow() failed. block=1, b_blocknr=8 __cleanup_mnt+0x16/0x20 fs/namespace.c:1181 b_state=0x00000029, b_size=512 task_work_run+0x1e4/0x290 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x2bd/0x310 arch/x86/entry/common.c:166 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 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 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 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 RIP: 0033:0x458417 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 RSP: 002b:00007ffc6d3379d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000458417 RDX: 00000000013dea13 RSI: 0000000000000002 RDI: 00007ffc6d338b40 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 RBP: 00007ffc6d338b40 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000005 R11: 0000000000000246 R12: 00000000013de940 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 R13: 0000000000000000 R14: 00000000000001bb R15: 000000000001bc37 Showing all locks held in the system: b_state=0x00000029, b_size=512 2 locks held by khungtaskd/892: device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 00000000f9cc6e1e b_state=0x00000029, b_size=512 (rcu_read_lock device loop0 blocksize: 4096 ){....}, at: check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] ){....}, at: watchdog+0x1ff/0xf60 kernel/hung_task.c:249 __find_get_block_slow() failed. block=1, b_blocknr=8 #1: 0000000049aa1a94 (tasklist_lock){.+.+}, at: debug_show_all_locks+0xde/0x34a kernel/locking/lockdep.c:4470 2 locks held by getty/4502: b_state=0x00000029, b_size=512 #0: device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 00000000df80b397 ( b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 &tty->ldisc_sem){++++} b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 , at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 #1: 00000000b15b895f (&ldata->atomic_read_lock b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 ){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 2 locks held by getty/4503: #0: __find_get_block_slow() failed. block=1, b_blocknr=8 00000000e09e83fd ( b_state=0x00000029, b_size=512 &tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: device loop0 blocksize: 4096 0000000084b57c47 ( __find_get_block_slow() failed. block=1, b_blocknr=8 &ldata->atomic_read_lock){+.+.} b_state=0x00000029, b_size=512 , at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4504: #0: 00000000198b3c17 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: device loop0 blocksize: 4096 00000000bd56de05 ( __find_get_block_slow() failed. block=1, b_blocknr=8 &ldata->atomic_read_lock){+.+.} b_state=0x00000029, b_size=512 , at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4505: #0: device loop0 blocksize: 4096 00000000305e2c0e ( __find_get_block_slow() failed. block=1, b_blocknr=8 &tty->ldisc_sem){++++} b_state=0x00000029, b_size=512 , at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000008ada3ecf device loop0 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 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 2 locks held by getty/4506: #0: 000000009fcd0f47 (&tty->ldisc_sem b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 ){++++} __find_get_block_slow() failed. block=1, b_blocknr=8 , at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: b_state=0x00000029, b_size=512 0000000069efdaf6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4507: #0: 00000000a048dd7c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 00000000d43d19e1 ( b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 &ldata->atomic_read_lock){+.+.} b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __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: 00000000bdd7f727 device loop0 blocksize: 4096 (&tty->ldisc_sem __find_get_block_slow() failed. block=1, b_blocknr=8 ){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 b_state=0x00000029, b_size=512 #1: 00000000d010538d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 device loop0 blocksize: 4096 1 lock held by syz-executor0/4578: #0: __find_get_block_slow() failed. block=1, b_blocknr=8 00000000f58e5270 ( b_state=0x00000029, b_size=512 &type->s_umount_key#46){+.+.}, at: deactivate_super+0x180/0x1b0 fs/super.c:346 device loop0 blocksize: 4096 ============================================= NMI backtrace for cpu 0 __find_get_block_slow() failed. block=1, b_blocknr=8 CPU: 0 PID: 892 Comm: khungtaskd Not tainted 4.17.0-rc5+ #52 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+0x1b9/0x294 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 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: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 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 kthread+0x345/0x410 kernel/kthread.c:240 __find_get_block_slow() failed. block=1, b_blocknr=8 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Sending NMI from CPU 0 to CPUs 1: b_state=0x00000029, b_size=512 NMI backtrace for cpu 1 CPU: 1 PID: 6841 Comm: kworker/u4:5 Not tainted 4.17.0-rc5+ #52 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:__write_once_size include/linux/compiler.h:215 [inline] RIP: 0010:write_comp_data+0x6c/0x70 kernel/kcov.c:144 RSP: 0018:ffff8801daf078d8 EFLAGS: 00000006 RAX: 0000000000000103 RBX: 00000000000001c0 RCX: ffffffff83525c90 RDX: 00000000000001c0 RSI: 00000000000001c0 RDI: 0000000000000006 RBP: ffff8801daf078d8 R08: ffff8801af09c080 R09: ffffed003b5e4928 R10: ffffed003b5e4928 R11: ffff8801daf24943 R12: 0000000000000000 R13: 00000000000001c0 R14: ffff8801daf24998 R15: ffff8801daf249c8 FS: 0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001b1730000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __sanitizer_cov_trace_cmp8+0x18/0x20 kernel/kcov.c:168 _find_next_bit lib/find_bit.c:54 [inline] find_next_bit+0x90/0x130 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+0x243/0xc50 kernel/time/timer.c:1662 run_timer_softirq+0x60/0x70 kernel/time/timer.c:1694 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:285 invoke_softirq kernel/softirq.c:365 [inline] irq_exit+0x1d1/0x200 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:525 [inline] smp_apic_timer_interrupt+0x17e/0x710 arch/x86/kernel/apic/apic.c:1052 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:783 [inline] RIP: 0010:console_trylock_spinning kernel/printk/printk.c:1678 [inline] RIP: 0010:vprintk_emit+0xbd0/0xdd0 kernel/printk/printk.c:1906 RSP: 0018:ffff8801ae9e6108 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffff8801af09c080 RBX: 0000000000000200 RCX: 1ffff10035e13925 RDX: 0000000000000000 RSI: ffffffff8160ce77 RDI: 0000000000000293 RBP: ffff8801ae9e6298 R08: ffff8801af09c8b8 R09: 0000000000000006 R10: ffff8801af09c080 R11: 0000000000000000 R12: 1ffffffff11a316d R13: 000000000000001e R14: ffffed0035d3cc3e R15: ffffffff8a6d3360 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:235 [inline] __find_get_block.cold.58+0x85/0x103 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/0x1740 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:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Code: 00 00 00 4e 8d 14 dd 28 00 00 00 4d 39 d0 72 1b 49 83 c1 01 4a 89 7c 10 e0 4a 89 74 10 e8 4a 89 54 10 f0 4a 89 4c d8 20 4c 89 08 <5d> c3 66 90 55 65 48 8b 04 25 c0 ed 01 00 65 8b 15 4f ae 88 7e INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.761 msecs