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-executor4:12287 blocked for more than 140 seconds. b_state=0x00000029, b_size=512 Not tainted 4.20.0-rc5+ #363 device loop0 blocksize: 4096 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. __find_get_block_slow() failed. block=1, b_blocknr=8 syz-executor4 D25352 12287 6161 0x00000004 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 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+0xfe/0x460 kernel/sched/core.c:3516 __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 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 sync_inodes_sb+0x33e/0x480 fs/fs-writeback.c:2417 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 sync_inodes_one_sb+0x59/0x70 fs/sync.c:74 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 iterate_supers+0x149/0x290 fs/super.c:633 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 ksys_sync+0xec/0x1e0 fs/sync.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 __ia32_sys_sync+0xe/0x20 fs/sync.c:124 __find_get_block_slow() failed. block=1, b_blocknr=8 do_syscall_64+0x1b9/0x820 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 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 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: 0033:0x457569 b_state=0x00000029, b_size=512 Code: Bad RIP value. device loop0 blocksize: 4096 RSP: 002b:00007f332a19fc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 000000000072c048 RCX: 0000000000457569 __find_get_block_slow() failed. block=1, b_blocknr=8 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 b_state=0x00000029, b_size=512 RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f332a1a06d4 device loop0 blocksize: 4096 R13: 00000000004c3216 R14: 00000000004d8918 R15: 00000000ffffffff __find_get_block_slow() failed. block=1, b_blocknr=8 INFO: task syz-executor4:12288 blocked for more than 140 seconds. b_state=0x00000029, b_size=512 Not tainted 4.20.0-rc5+ #363 device loop0 blocksize: 4096 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. __find_get_block_slow() failed. block=1, b_blocknr=8 syz-executor4 D25128 12288 6161 0x00000004 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 device loop0 blocksize: 4096 schedule+0xfe/0x460 kernel/sched/core.c:3516 __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 wb_wait_for_completion+0x1f9/0x2d0 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 sync_inodes_sb+0x33e/0x480 fs/fs-writeback.c:2417 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 sync_inodes_one_sb+0x59/0x70 fs/sync.c:74 b_state=0x00000029, b_size=512 iterate_supers+0x149/0x290 fs/super.c:633 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 ksys_sync+0xec/0x1e0 fs/sync.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 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __ia32_sys_sync+0xe/0x20 fs/sync.c:124 __find_get_block_slow() failed. block=1, b_blocknr=8 do_syscall_64+0x1b9/0x820 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 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: 0033:0x457569 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 Code: Bad RIP value. b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 RSP: 002b:00007f332a17ec78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 RAX: ffffffffffffffda RBX: 000000000072c0e8 RCX: 0000000000457569 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 b_state=0x00000029, b_size=512 RBP: 000000000072c0e0 R08: 0000000000000000 R09: 0000000000000000 device loop0 blocksize: 4096 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f332a17f6d4 __find_get_block_slow() failed. block=1, b_blocknr=8 R13: 00000000004c3216 R14: 00000000004d8918 R15: 00000000ffffffff b_state=0x00000029, b_size=512 Showing all locks held in the system: device loop0 blocksize: 4096 7 locks held by kworker/u4:0/7: __find_get_block_slow() failed. block=1, b_blocknr=8 1 lock held by khungtaskd/1019: b_state=0x00000029, b_size=512 #0: 0000000047483a1e (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 device loop0 blocksize: 4096 1 lock held by rsyslogd/5935: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 000000003e0a2456 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 b_state=0x00000029, b_size=512 2 locks held by getty/6025: device loop0 blocksize: 4096 #0: 00000000e1225992 (&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: 0000000031927a8f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 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/6026: b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 #0: 00000000327eead7 (&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: 00000000da7a666d (&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/6027: device loop0 blocksize: 4096 #0: 00000000401f3f66 (&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: 00000000dc06f659 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 2 locks held by getty/6028: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 000000009f0cfbda (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 #1: 000000006f2a525d (&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/6029: #0: 000000000f380bdf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 b_state=0x00000029, b_size=512 #1: 00000000dfd2f475 (&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/6030: #0: 00000000d2b2dde5 (&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: 000000004954e0ce (&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/6031: device loop0 blocksize: 4096 #0: 00000000ee0506f3 (&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: 00000000b4e53d22 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 1 lock held by syz-executor4/12287: b_state=0x00000029, b_size=512 #0: 0000000010feef7b (&type->s_umount_key#49){++++}, at: iterate_supers+0xe2/0x290 fs/super.c:631 device loop0 blocksize: 4096 1 lock held by syz-executor4/12288: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 0000000010feef7b (&type->s_umount_key#49){++++}, at: iterate_supers+0xe2/0x290 fs/super.c:631 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 NMI backtrace for cpu 0 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 CPU: 0 PID: 1019 Comm: khungtaskd Not tainted 4.20.0-rc5+ #363 b_state=0x00000029, b_size=512 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: device loop0 blocksize: 4096 __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 b_state=0x00000029, b_size=512 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a lib/nmi_backtrace.c:62 device loop0 blocksize: 4096 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xb51/0x1060 kernel/hung_task.c:289 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 kthread+0x35a/0x440 kernel/kthread.c:246 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: __find_get_block_slow() failed. block=1, b_blocknr=8 NMI backtrace for cpu 1 CPU: 1 PID: 7 Comm: kworker/u4:0 Not tainted 4.20.0-rc5+ #363 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:__sanitizer_cov_trace_pc+0x1/0x50 kernel/kcov.c:94 Code: 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 <48> 89 e5 48 8b 75 08 65 48 8b 04 25 40 ee 01 00 65 8b 15 f8 51 82 RSP: 0018:ffff8881d9ae5a70 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 00000000fffffffe RCX: ffffffff87d6e036 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: ffff8881d9ae5ba0 R08: ffff8881d9ada1c0 R09: ffffed103b35cbab R10: ffffed103b35cbab R11: 0000000000000003 R12: 0000000000000000 R13: 000000000000000a R14: 0000000000000002 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001cb955000 CR4: 00000000001406e0 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:231 [inline] __find_get_block.cold.57+0x3a/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 __writeback_inodes_wb+0x1b9/0x340 fs/fs-writeback.c:1649 wb_writeback+0xa73/0xfc0 fs/fs-writeback.c:1758 wb_check_start_all fs/fs-writeback.c:1882 [inline] wb_do_writeback fs/fs-writeback.c:1908 [inline] wb_workfn+0xee9/0x1790 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 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.718 msecs