BTRFS info (device loop3): has skinny extents
BTRFS error (device loop3): bad tree block start, want 5242880 have 0
BTRFS warning (device loop3): failed to read tree root
------------[ cut here ]------------
WARNING: CPU: 1 PID: 8647 at fs/btrfs/volumes.c:1086 close_fs_devices.part.0.cold+0x11/0x30 fs/btrfs/volumes.c:1086
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 8647 Comm: syz-executor444 Not tainted 4.19.163-syzkaller #0
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+0x1fc/0x2fe lib/dump_stack.c:118
 panic+0x26a/0x50e kernel/panic.c:186
 __warn.cold+0x20/0x61 kernel/panic.c:541
 report_bug+0x262/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 fixup_bug arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x1d7/0x310 arch/x86/kernel/traps.c:296
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038
RIP: 0010:close_fs_devices.part.0.cold+0x11/0x30 fs/btrfs/volumes.c:1086
Code: c7 c7 a0 f4 a4 88 e8 7a b1 56 fe 0f 0b 49 c7 c4 ea ff ff ff e9 d7 06 ff ff e8 d8 b7 6b fe 48 c7 c7 a0 f4 a4 88 e8 5b b1 56 fe <0f> 0b e9 b4 0e ff ff e8 c0 b7 6b fe 48 c7 c7 a0 f4 a4 88 e8 43 b1
RSP: 0018:ffff8880a249f600 EFLAGS: 00010282
RAX: 0000000000000024 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff814fdbb1 RDI: ffffed1014493eb2
RBP: ffff8880aa2fe000 R08: 0000000000000024 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff8880a9aa2580 R14: ffff88809003ede0 R15: ffff8880b4dc7b00
 close_fs_devices fs/btrfs/volumes.c:1113 [inline]
 btrfs_close_devices+0x95/0x1f0 fs/btrfs/volumes.c:1099
 open_ctree+0x26b/0x61e0 fs/btrfs/disk-io.c:3326
 btrfs_fill_super fs/btrfs/super.c:1209 [inline]
 btrfs_mount_root+0x12e5/0x1830 fs/btrfs/super.c:1613
 mount_fs+0xa3/0x30c fs/super.c:1261
 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
 vfs_kern_mount+0x3c/0x60 fs/namespace.c:951
 btrfs_mount+0x23a/0xa93 fs/btrfs/super.c:1681
 mount_fs+0xa3/0x30c fs/super.c:1261
 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2469 [inline]
 do_mount+0x113c/0x2f10 fs/namespace.c:2799
 ksys_mount+0xcf/0x130 fs/namespace.c:3015
 __do_sys_mount fs/namespace.c:3029 [inline]
 __se_sys_mount fs/namespace.c:3026 [inline]
 __x64_sys_mount+0xba/0x150 fs/namespace.c:3026
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x44deba
Code: b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 ad a0 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 8a a0 fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007f1a2472abc8 EFLAGS: 00000293 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000044deba
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f1a2472ac10
RBP: 00007f1a2472b6d0 R08: 00007f1a2472ac50 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 00007f1a2472ac50
R13: 00007f1a2472ac10 R14: 0000000000000003 R15: 0000000000000001
Kernel Offset: disabled
Rebooting in 86400 seconds..