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-executor0:20500 blocked for more than 140 seconds. b_state=0x00000029, b_size=512 Not tainted 4.20.0+ #4 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 syz-executor0 D24840 20500 8389 0x00000004 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 Call Trace: b_state=0x00000029, b_size=512 context_switch kernel/sched/core.c:2831 [inline] __schedule+0x897/0x1e90 kernel/sched/core.c:3472 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 schedule+0xfe/0x350 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 __rwsem_down_write_failed_common+0xa4d/0x1620 kernel/locking/rwsem-xadd.c:577 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 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:606 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0xa5/0x130 kernel/locking/rwsem.c:72 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 deactivate_super fs/super.c:359 [inline] deactivate_super+0x2a9/0x320 fs/super.c:356 __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 cleanup_mnt+0xbf/0x160 fs/namespace.c:1098 b_state=0x00000029, b_size=512 __cleanup_mnt+0x16/0x20 fs/namespace.c:1105 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 task_work_run+0x1f4/0x2b0 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:188 [inline] exit_to_usermode_loop+0x32a/0x3b0 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 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:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x696/0x800 arch/x86/entry/common.c:293 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: 0033:0x457ec9 b_state=0x00000029, b_size=512 Code: Bad RIP value. device loop0 blocksize: 4096 RSP: 002b:00007f1950139c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 __find_get_block_slow() failed. block=1, b_blocknr=8 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000457ec9 b_state=0x00000029, b_size=512 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000280 device loop0 blocksize: 4096 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 __find_get_block_slow() failed. block=1, b_blocknr=8 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f195013a6d4 b_state=0x00000029, b_size=512 R13: 00000000004c6941 R14: 00000000004dba70 R15: 00000000ffffffff device loop0 blocksize: 4096 Showing all locks held in the system: __find_get_block_slow() failed. block=1, b_blocknr=8 7 locks held by kworker/u4:2/128: b_state=0x00000029, b_size=512 1 lock held by khungtaskd/1040: #0: 000000009637f257 (rcu_read_lock){....}, at: debug_show_all_locks+0xc6/0x41d kernel/locking/lockdep.c:4389 1 lock held by rsyslogd/8207: device loop0 blocksize: 4096 2 locks held by getty/8351: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 00000000ad631970 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 #1: 0000000026e5912d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 __find_get_block_slow() failed. block=1, b_blocknr=8 2 locks held by getty/8352: b_state=0x00000029, b_size=512 #0: 00000000693f6ed8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 #1: 00000000bc1c249e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 b_state=0x00000029, b_size=512 2 locks held by getty/8353: device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 0000000088eca207 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 b_state=0x00000029, b_size=512 #1: 00000000d6dfd76c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 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/8354: b_state=0x00000029, b_size=512 #0: 0000000089b92b24 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 #1: 0000000042b75935 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 b_state=0x00000029, b_size=512 2 locks held by getty/8355: device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 000000008fb096a1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 b_state=0x00000029, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 #1: 00000000c543662b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 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/8356: b_state=0x00000029, b_size=512 #0: 000000003f9a0d77 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 #1: 000000002bd3b700 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 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/8357: b_state=0x00000029, b_size=512 #0: 000000002b0e20a7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 #1: 00000000492b1471 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 b_state=0x00000029, b_size=512 3 locks held by kworker/u4:7/9856: device loop0 blocksize: 4096 1 lock held by syz-executor0/20500: __find_get_block_slow() failed. block=1, b_blocknr=8 #0: 00000000e91b1d3a (&type->s_umount_key#66){++++}, at: deactivate_super fs/super.c:359 [inline] #0: 00000000e91b1d3a (&type->s_umount_key#66){++++}, at: deactivate_super+0x2a9/0x320 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 0 b_state=0x00000029, b_size=512 CPU: 0 PID: 1040 Comm: khungtaskd Not tainted 4.20.0+ #4 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+0x1db/0x2d0 lib/dump_stack.c:113 device loop0 blocksize: 4096 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62 __find_get_block_slow() failed. block=1, b_blocknr=8 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 b_state=0x00000029, b_size=512 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xbd2/0x10b0 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 kthread+0x357/0x430 kernel/kthread.c:246 device loop0 blocksize: 4096 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 __find_get_block_slow() failed. block=1, b_blocknr=8 Sending NMI from CPU 0 to CPUs 1: b_state=0x00000029, b_size=512 NMI backtrace for cpu 1 CPU: 1 PID: 128 Comm: kworker/u4:2 Not tainted 4.20.0+ #4 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:write_comp_data+0x0/0x70 kernel/kcov.c:121 Code: 83 fa 02 75 20 48 8b 88 e0 12 00 00 8b 80 dc 12 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 5d c3 0f 1f 00 <65> 4c 8b 04 25 40 ee 01 00 65 8b 05 c0 6b 80 7e a9 00 01 1f 00 75 RSP: 0018:ffff8880a92c6300 EFLAGS: 00000082 RAX: ffff8880a92ba340 RBX: 0000000000000000 RCX: ffffffff87ed3dfd RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: ffff8880a92c6308 R08: ffff8880a92ba340 R09: ffffed1015258ccd R10: ffffed1015258ccc R11: ffff8880a92c6660 R12: ffff8880a92c6662 R13: ffff8881292c665f R14: 0000000000000002 R15: ffff8880a92c6661 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000000a4fa6000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: number+0x56d/0xc80 lib/vsprintf.c:477 vsnprintf+0x2a9/0x1b10 lib/vsprintf.c:2462 sprintf+0xc0/0x100 lib/vsprintf.c:2598 print_time kernel/printk/printk.c:1239 [inline] print_prefix kernel/printk/printk.c:1251 [inline] msg_print_text+0x3f3/0x450 kernel/printk/printk.c:1262 console_unlock+0x43f/0x11e0 kernel/printk/printk.c:2383 vprintk_emit+0x370/0x960 kernel/printk/printk.c:1931 vprintk_default+0x28/0x30 kernel/printk/printk.c:1958 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:1991 __find_get_block_slow fs/buffer.c:235 [inline] __find_get_block fs/buffer.c:1294 [inline] __find_get_block.cold+0x81/0xfb fs/buffer.c:1288 __getblk_slow fs/buffer.c:1039 [inline] __getblk_gfp+0x295/0xd20 fs/buffer.c:1320 __bread_gfp+0x2f/0x300 fs/buffer.c:1354 sb_bread include/linux/buffer_head.h:307 [inline] __fat_write_inode+0x33a/0xb70 fs/fat/inode.c:859 fat_write_inode+0x96/0x190 fs/fat/inode.c:908 write_inode fs/fs-writeback.c:1176 [inline] __writeback_single_inode+0xef1/0x1620 fs/fs-writeback.c:1375 writeback_sb_inodes+0x762/0x1260 fs/fs-writeback.c:1580 __writeback_inodes_wb+0x16d/0x3d0 fs/fs-writeback.c:1649 wb_writeback+0xa2d/0xf70 fs/fs-writeback.c:1758 wb_check_old_data_flush fs/fs-writeback.c:1860 [inline] wb_do_writeback fs/fs-writeback.c:1913 [inline] wb_workfn+0xf7f/0x16f0 fs/fs-writeback.c:1942 process_one_work+0xd0c/0x1ce0 kernel/workqueue.c:2153 worker_thread+0x143/0x14a0 kernel/workqueue.c:2296 kthread+0x357/0x430 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: 2.142 msecs