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-executor0:4535 blocked for more than 120 seconds. b_state=0x00000029, b_size=512 Not tainted 4.17.0-rc7+ #78 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D device loop0 blocksize: 4096 21032 4535 1 0x00000004 __find_get_block_slow() failed. block=1, b_blocknr=8 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 schedule+0xef/0x430 kernel/sched/core.c:3545 __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+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 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 __writeback_inodes_sb_nr+0x3e8/0x550 fs/fs-writeback.c:2340 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 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 writeback_inodes_sb_nr fs/fs-writeback.c:2357 [inline] writeback_inodes_sb+0x27/0x30 fs/fs-writeback.c:2372 device loop0 blocksize: 4096 __sync_filesystem fs/sync.c:36 [inline] sync_filesystem+0x15f/0x310 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+0xd7/0x520 fs/super.c:439 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+0xa4/0x100 fs/super.c:1201 b_state=0x00000029, b_size=512 deactivate_locked_super+0x97/0x100 fs/super.c:326 deactivate_super+0x188/0x1b0 fs/super.c:357 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 device loop0 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 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 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x2bd/0x310 arch/x86/entry/common.c:166 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 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 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458417 __find_get_block_slow() failed. block=1, b_blocknr=8 RSP: 002b:00007ffe9c158d18 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000458417 RDX: 00000000025839a3 RSI: 0000000000000002 RDI: 00007ffe9c159e80 __find_get_block_slow() failed. block=1, b_blocknr=8 RBP: 00007ffe9c159e80 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000005 R11: 0000000000000246 R12: 0000000002583940 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 R13: 0000000000000000 R14: 000000000000013f R15: 00000000000196ab Showing all locks held in the system: b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 2 locks held by khungtaskd/893: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 00000000be50d036 ( b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 rcu_read_lock){....}, at: check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] rcu_read_lock){....}, at: watchdog+0x1ff/0xf60 kernel/hung_task.c:249 __find_get_block_slow() failed. block=1, b_blocknr=8 #1: 00000000c5a59ab5 ( b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 tasklist_lock){.+.+}, at: debug_show_all_locks+0xde/0x34a kernel/locking/lockdep.c:4470 2 locks held by getty/4464: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 000000009bf42119 ( b_state=0x00000029, b_size=512 &tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 device loop0 blocksize: 4096 #1: 00000000515f76f1 ( __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 b_state=0x00000029, b_size=512 2 locks held by getty/4465: #0: 00000000a5b0d8ea (&tty->ldisc_sem){++++} device loop0 blocksize: 4096 , at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: __find_get_block_slow() failed. block=1, b_blocknr=8 000000003346cffc (&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/4466: #0: device loop0 blocksize: 4096 000000002b46968d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000c00db6d7 __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/4467: #0: 00000000860d2e6a device loop0 blocksize: 4096 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 __find_get_block_slow() failed. block=1, b_blocknr=8 #1: 00000000c6162e4e ( b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 &ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 __find_get_block_slow() failed. block=1, b_blocknr=8 2 locks held by getty/4468: #0: b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 00000000cba28d5c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: __find_get_block_slow() failed. block=1, b_blocknr=8 000000008648a0e8 (&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/4469: #0: device loop0 blocksize: 4096 000000005a602251 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000e0c414c9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4470: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 00000000e0dd2f2a 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 #1: b_state=0x00000029, b_size=512 000000002738803d (&ldata->atomic_read_lock device loop0 blocksize: 4096 ){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 1 lock held by syz-executor0/4535: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 00000000fecc0404 ( b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 &type->s_umount_key#46){+.+.} b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 , at: deactivate_super+0x180/0x1b0 fs/super.c:356 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 CPU: 1 PID: 893 Comm: khungtaskd Not tainted 4.17.0-rc7+ #78 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: b_state=0x00000029, b_size=512 __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 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 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 kthread+0x345/0x410 kernel/kthread.c:240 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 b_state=0x00000029, b_size=512 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 144 Comm: kworker/u4:3 Not tainted 4.17.0-rc7+ #78 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:update_sd_lb_stats+0xf10/0x2c30 kernel/sched/fair.c:8297 RSP: 0018:ffff8801dae07070 EFLAGS: 00000a06 RAX: 1ffff1003b5c0e2e RBX: ffff8801dae07508 RCX: 0000000000000007 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8801dae07544 RBP: ffff8801dae07398 R08: 0000000000000000 R09: 0000000000000016 R10: ffff8801dae07528 R11: 0000000000000975 R12: 0000000000000002 R13: dffffc0000000000 R14: ffff8801dae07488 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f43fc211000 CR3: 00000001b5275000 CR4: 00000000001406f0 DR0: 000000000000b8c4 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: find_busiest_group+0xf8/0x1c60 kernel/sched/fair.c:8540 load_balance+0x62f/0x3580 kernel/sched/fair.c:8805 rebalance_domains+0x809/0xd80 kernel/sched/fair.c:9221 run_rebalance_domains+0x351/0x4a0 kernel/sched/fair.c:9843 __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:ffff8801d9086108 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 RAX: ffff8801d974c540 RBX: 0000000000000200 RCX: 1ffff1003b2e99bd RDX: 0000000000000000 RSI: ffffffff8160d247 RDI: 0000000000000293 RBP: ffff8801d9086298 R08: ffff8801d974cd78 R09: 0000000000000006 R10: ffff8801d974c540 R11: 0000000000000000 R12: 1ffffffff11a31ad R13: 000000000000001e R14: ffffed003b210c3e 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: 8b 85 38 fd ff ff 31 d2 48 c1 e8 03 4c 01 e8 c7 00 00 00 00 00 c7 40 04 00 00 00 00 66 89 50 08 48 8b 85 68 fd ff ff 48 c1 e8 03 <42> c6 04 28 01 48 8b 85 20 fd ff ff 48 c1 e8 03 42 80 3c 28 00 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.108 msecs