device loop0 blocksize: 2048 __find_get_block_slow() failed. block=1, b_blocknr=0 b_state=0x00000029, b_size=4096 device loop0 blocksize: 2048 __find_get_block_slow() failed. block=1, b_blocknr=0 INFO: task syz-executor0:30123 blocked for more than 140 seconds. Not tainted 4.14.71+ #8 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D29624 30123 1850 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:565 [inline] rwsem_down_write_failed+0x390/0x730 kernel/locking/rwsem-xadd.c:594 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:105 __down_write arch/x86/include/asm/rwsem.h:126 [inline] down_write+0x4f/0x90 kernel/locking/rwsem.c:56 grab_super+0x59/0x170 fs/super.c:373 sget_userns+0x2ae/0xc30 fs/super.c:504 sget+0xcd/0x110 fs/super.c:572 mount_bdev+0xde/0x370 fs/super.c:1122 mount_fs+0x28f/0x31a fs/super.c:1255 vfs_kern_mount.part.9+0xce/0x4a0 fs/namespace.c:1056 vfs_kern_mount fs/namespace.c:1038 [inline] do_new_mount fs/namespace.c:2561 [inline] do_mount+0x404/0x26e0 fs/namespace.c:2891 SYSC_mount fs/namespace.c:3107 [inline] SyS_mount+0xe5/0x100 fs/namespace.c:3084 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x457679 RSP: 002b:00007f8ecd116c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f8ecd1176d4 RCX: 0000000000457679 RDX: 0000000020000100 RSI: 00000000200000c0 RDI: 0000000020000080 RBP: 000000000072bfa0 R08: 0000000020000280 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d3b58 R14: 00000000004c297a R15: 0000000000000001 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x74/0x20f kernel/locking/lockdep.c:4541 1 lock held by rsyslogd/1634: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0xa2/0xc0 fs/file.c:768 2 locks held by getty/1762: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x20/0x80 drivers/tty/tty_ldisc.c:275 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1ff/0x15e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor1/21977: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x20/0x80 drivers/tty/tty_ldisc.c:275 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1ff/0x15e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor0/30123: #0: (&bdev->bd_fsfreeze_mutex){+.+.}, at: [] mount_bdev+0x81/0x370 fs/super.c:1116 #1: (&type->s_umount_key#41){++++}, at: [] grab_super+0x59/0x170 fs/super.c:373 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.71+ #8 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x11b lib/dump_stack.c:53 nmi_cpu_backtrace.cold.0+0x47/0x85 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x121/0x146 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline] watchdog+0x574/0xa70 kernel/hung_task.c:252 kthread+0x348/0x420 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 30115 Comm: syz-executor0 Not tainted 4.14.71+ #8 task: ffff8801d2ea1780 task.stack: ffff8801a9f98000 RIP: 0010:outb arch/x86/include/asm/io.h:309 [inline] RIP: 0010:io_serial_out+0x68/0x80 drivers/tty/serial/8250/8250_port.c:456 RSP: 0018:ffff8801a9f9f6b8 EFLAGS: 00000002 RAX: 0000000000000074 RBX: 00000000000003f8 RCX: 0000000000000000 RDX: 00000000000003f8 RSI: ffffc90000d1d000 RDI: ffffffff9f11d998 RBP: ffffffff9f11d960 R08: 0000000000007292 R09: ffffffff9e2fbb30 R10: ffff8801d2ea2028 R11: 0000000000000001 R12: 0000000000000074 R13: ffffffff9bb4f430 R14: dffffc0000000000 R15: ffffffff9e7acfc4 FS: 00007f8ecd138700(0000) GS:ffff8801db800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000708934 CR3: 00000001c68f2001 CR4: 00000000001606b0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: uart_console_write+0x4b/0xd0 drivers/tty/serial/serial_core.c:1883 serial8250_console_write+0x51b/0x800 drivers/tty/serial/8250/8250_port.c:3250 call_console_drivers kernel/printk/printk.c:1574 [inline] console_unlock+0x5b9/0xb50 kernel/printk/printk.c:2242 vprintk_emit+0x112/0x150 kernel/printk/printk.c:1766 vprintk_func+0x58/0x159 kernel/printk/printk_safe.c:401 printk+0xa7/0xcf kernel/printk/printk.c:1838 __find_get_block_slow fs/buffer.c:239 [inline] __find_get_block.cold.22+0x36/0xf5 fs/buffer.c:1356 __getblk_slow fs/buffer.c:1099 [inline] __getblk_gfp+0x186/0x720 fs/buffer.c:1382 __bread_gfp+0x28/0x1e0 fs/buffer.c:1416 sb_bread include/linux/buffer_head.h:307 [inline] read_raw_super_block fs/f2fs/super.c:2494 [inline] f2fs_fill_super+0x287/0x5cd0 fs/f2fs/super.c:2712 mount_bdev+0x2ab/0x370 fs/super.c:1149 mount_fs+0x28f/0x31a fs/super.c:1255 vfs_kern_mount.part.9+0xce/0x4a0 fs/namespace.c:1056 vfs_kern_mount fs/namespace.c:1038 [inline] do_new_mount fs/namespace.c:2561 [inline] do_mount+0x404/0x26e0 fs/namespace.c:2891 SYSC_mount fs/namespace.c:3107 [inline] SyS_mount+0xe5/0x100 fs/namespace.c:3084 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x457679 RSP: 002b:00007f8ecd137c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f8ecd1386d4 RCX: 0000000000457679 RDX: 0000000020000100 RSI: 00000000200000c0 RDI: 0000000020000080 RBP: 000000000072bf00 R08: 0000000020000280 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d3b58 R14: 00000000004c297a R15: 0000000000000000 Code: 8d d1 00 00 00 48 8d 7d 38 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 d3 e3 80 3c 02 00 75 15 03 5d 38 44 89 e0 89 da ee <5b> 5d 41 5c c3 e8 8e de 7d ff eb c7 e8 b7 de 7d ff eb e4 0f 1f