BTRFS warning (device loop2): loop2 checksum verify failed on 30621696 wanted 82D1CDB found B3E316F9 level 0 BTRFS error (device loop2): bad tree block start 0 30621696 BTRFS warning (device loop2): failed to read tree root BTRFS error (device loop2): open_ctree failed INFO: task syz-executor.0:29357 blocked for more than 140 seconds. Not tainted 4.14.216-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29848 29357 8036 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:588 [inline] rwsem_down_write_failed+0x343/0x6d0 kernel/locking/rwsem-xadd.c:617 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+0x55/0x140 fs/super.c:373 sget_userns+0x2b1/0xc10 fs/super.c:504 sget+0xd1/0x110 fs/super.c:572 mount_bdev+0xcd/0x360 fs/super.c:1107 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0xe53/0x2a00 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3072 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45e219 RSP: 002b:00007f8fa4d19c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e219 RDX: 0000000020000000 RSI: 0000000020000180 RDI: 0000000020000380 RBP: 000000000119c078 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c034 R13: 00007ffc343bc0bf R14: 00007f8fa4d1a9c0 R15: 000000000119c034 Showing all locks held in the system: 1 lock held by khungtaskd/1531: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 2 locks held by syz-executor.0/29357: #0: (&bdev->bd_fsfreeze_mutex){+.+.}, at: [] mount_bdev+0x71/0x360 fs/super.c:1101 #1: (&type->s_umount_key#70){+.+.}, at: [] grab_super+0x55/0x140 fs/super.c:373 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1531 Comm: khungtaskd Not tainted 4.14.216-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 29335 Comm: syz-executor.0 Not tainted 4.14.216-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880599621c0 task.stack: ffff88805c480000 RIP: 0010:debug_lockdep_rcu_enabled+0x5b/0xe0 kernel/rcu/update.c:299 RSP: 0018:ffff88805c487690 EFLAGS: 00000006 RAX: 0000000000000003 RBX: 1ffff1100b890ed7 RCX: 1ffffffff127a00c RDX: 0000000000000004 RSI: 0000000000000002 RDI: ffff888059962a44 RBP: ffff8880907f0c90 R08: ffffffff8b9b0210 R09: 0000000000040243 R10: 0000000000000000 R11: ffff8880599621c0 R12: ffffffff81928abb R13: ffff8880599621c0 R14: 0000000000000001 R15: ffffea0002d83940 FS: 00007f8fa4d3b700(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc914585000 CR3: 00000000a902c000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x5a6/0x870 kernel/locking/lockdep.c:4016 __raw_spin_unlock include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_unlock+0x17/0x40 kernel/locking/spinlock.c:184 spin_unlock include/linux/spinlock.h:357 [inline] __find_get_block_slow fs/buffer.c:250 [inline] __find_get_block+0x65b/0xc40 fs/buffer.c:1357 __getblk_slow+0x127/0x7a0 fs/buffer.c:1100 __getblk_gfp fs/buffer.c:1383 [inline] __bread_gfp+0x206/0x2e0 fs/buffer.c:1428 sb_bread include/linux/buffer_head.h:309 [inline] udf_tread+0xe1/0x130 fs/udf/misc.c:44 udf_read_tagged+0x40/0x4c0 fs/udf/misc.c:210 udf_check_anchor_block+0x18a/0x590 fs/udf/super.c:1816 udf_scan_anchors+0x321/0x530 fs/udf/super.c:1878 udf_find_anchor fs/udf/super.c:1913 [inline] udf_load_vrs+0x5a1/0xa90 fs/udf/super.c:1978 udf_fill_super+0x715/0x1680 fs/udf/super.c:2170 mount_bdev+0x2b3/0x360 fs/super.c:1134 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0xe53/0x2a00 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3072 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45e219 RSP: 002b:00007f8fa4d3ac68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e219 RDX: 0000000020000000 RSI: 0000000020000180 RDI: 0000000020000380 RBP: 000000000119bfd0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffc343bc0bf R14: 00007f8fa4d3b9c0 R15: 000000000119bf8c Code: 35 ef b5 c2 08 85 f6 74 79 48 c7 c0 60 00 3d 89 48 ba 00 00 00 00 00 fc ff df 48 89 c1 83 e0 07 48 c1 e9 03 83 c0 03 0f b6 14 11 <38> d0 7c 04 84 d2 75 64 8b 0d 17 f9 f6 07 85 c9 74 45 65 48 8b