b_state=0x0000012d, b_size=512 device loop0 blocksize: 4096 __find_get_block_slow() failed. block=1, b_blocknr=8 b_state=0x0000012d, b_size=512 device loop0 blocksize: 4096 INFO: task syz-executor0:7208 blocked for more than 140 seconds. Not tainted 4.9.113-g47bbcd6 #10 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D29432 7208 3849 0x00000004 ffff8801cdebc800 ffff8801cfd1d500 ffff8801d30f9a40 ffff8801d0841800 ffff8801db221c18 ffff8801a44e7728 ffffffff839e909d ffffffff81235647 0000000000000000 ffff8801cdebd0c0 0000000600000007 ffff8801db2224e8 Call Trace: [] schedule+0x7f/0x1b0 kernel/sched/core.c:3553 [] __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:526 [inline] [] rwsem_down_write_failed+0x598/0x990 kernel/locking/rwsem-xadd.c:555 [] call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:105 [] __down_write arch/x86/include/asm/rwsem.h:125 [inline] [] down_write+0x5c/0xa0 kernel/locking/rwsem.c:54 [] inode_lock include/linux/fs.h:766 [inline] [] do_truncate2+0x128/0x1f0 fs/open.c:61 [] handle_truncate fs/namei.c:2990 [inline] [] do_last fs/namei.c:3419 [inline] [] path_openat+0x251e/0x3590 fs/namei.c:3534 [] do_filp_open+0x197/0x270 fs/namei.c:3568 [] do_sys_open+0x30d/0x5c0 fs/open.c:1072 [] SYSC_open fs/open.c:1090 [inline] [] SyS_open fs/open.c:1085 [inline] [] SYSC_creat fs/open.c:1110 [inline] [] SyS_creat+0x27/0x30 fs/open.c:1108 [] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Showing all locks held in the system: 2 locks held by khungtaskd/519: #0: (rcu_read_lock){......}, at: [] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline] #0: (rcu_read_lock){......}, at: [] watchdog+0x11c/0xa20 kernel/hung_task.c:239 #1: (tasklist_lock){.+.+..}, at: [] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336 1 lock held by rsyslogd/3682: #0: (&f->f_pos_lock){+.+.+.}, at: [] __fdget_pos+0xac/0xd0 fs/file.c:781 2 locks held by getty/3778: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor0/7208: #0: (sb_writers#10){.+.+.+}, at: [] sb_start_write include/linux/fs.h:1573 [inline] #0: (sb_writers#10){.+.+.+}, at: [] mnt_want_write+0x3f/0xb0 fs/namespace.c:391 #1: (&sb->s_type->i_mutex_key#14){+.+.+.}, at: [] inode_lock include/linux/fs.h:766 [inline] #1: (&sb->s_type->i_mutex_key#14){+.+.+.}, at: [] do_truncate2+0x128/0x1f0 fs/open.c:61 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 519 Comm: khungtaskd Not tainted 4.9.113-g47bbcd6 #10 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801d9777d08 ffffffff81eb32a9 0000000000000000 0000000000000001 0000000000000001 0000000000000001 ffffffff810b9bd0 ffff8801d9777d40 ffffffff81ebe5a7 0000000000000001 0000000000000000 0000000000000003 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99 [] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60 [] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [] check_hung_task kernel/hung_task.c:125 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline] [] watchdog+0x6b4/0xa20 kernel/hung_task.c:239 [] kthread+0x26d/0x300 kernel/kthread.c:211 [] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 1 Comm: init Not tainted 4.9.113-g47bbcd6 #10 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801d99b0000 task.stack: ffff8801d99b8000 RIP: 0010:[] c [] inb arch/x86/include/asm/io.h:316 [inline] RIP: 0010:[] c [] io_serial_in+0x6b/0x90 drivers/tty/serial/8250/8250_port.c:414 RSP: 0018:ffff8801d99bf520 EFLAGS: 00000002 RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: ffffffff8214fb01 RDI: ffffffff864aae78 RBP: ffff8801d99bf530 R08: ffff8801d99b0938 R09: 0000000000000001 R10: ffff8801d99b0000 R11: 1ffff1003b336122 R12: ffffffff864aae40 R13: 0000000000000020 R14: fffffbfff0c9560f R15: fffffbfff0c955d1 FS: 00007f42666d97a0(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc8903a2188 CR3: 00000001cdaba000 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff864aae40c 000000000000270fc ffff8801d99bf580c ffffffff82151724c ffff8801d99bf5b8c ffffffff864aae88c ffffffff864ab07ac ffffffff864aae40c 0000000000000069c ffffffff82151870c dffffc0000000000c 0000000000000069c Call Trace: [] serial_in drivers/tty/serial/8250/8250.h:111 [inline] [] wait_for_xmitr+0x94/0x1e0 drivers/tty/serial/8250/8250_port.c:1998 [] serial8250_console_putchar+0x1f/0x60 drivers/tty/serial/8250/8250_port.c:3104 [] uart_console_write+0x59/0xf0 drivers/tty/serial/serial_core.c:1859 [] serial8250_console_write+0x528/0x820 drivers/tty/serial/8250/8250_port.c:3170 [] univ8250_console_write+0x5f/0x70 drivers/tty/serial/8250/8250_core.c:594 [] call_console_drivers.isra.18.constprop.28+0x1ad/0x360 kernel/printk/printk.c:1589 [] console_unlock+0x42f/0xb40 kernel/printk/printk.c:2449 [] console_device+0x97/0xc0 kernel/printk/printk.c:2557 [] tty_lookup_driver drivers/tty/tty_io.c:2003 [inline] [] tty_open_by_driver drivers/tty/tty_io.c:2048 [inline] [] tty_open+0x71a/0xe20 drivers/tty/tty_io.c:2125 [] chrdev_open+0x22d/0x4c0 fs/char_dev.c:392 [] do_dentry_open+0x703/0xc80 fs/open.c:766 [] vfs_open+0x11c/0x210 fs/open.c:879 [] do_last fs/namei.c:3410 [inline] [] path_openat+0x758/0x3590 fs/namei.c:3534 [] do_filp_open+0x197/0x270 fs/namei.c:3568 [] do_sys_open+0x30d/0x5c0 fs/open.c:1072 [] SYSC_open fs/open.c:1090 [inline] [] SyS_open+0x2d/0x40 fs/open.c:1085 [] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Code: c24 cc9 c00 c00 c00 c49 c8d c7c c24 c38 c48 cb8 c00 c00 c00 c00 c00 cfc cff cdf c48 c89 cfa c48 cc1 cea c03 cd3 ce3 c80 c3c c02 c00 c75 c17 c41 c03 c5c c24 c38 c89 cda cec c<5b> c0f cb6 cc0 c41 c5c c5d cc3 ce8 c58 cc0 c3e cff ceb cc2 ce8 cb1 cc0 c3e cff ceb c