BTRFS info (device loop0): using crc32c (crc32c-intel) checksum algorithm
BTRFS info (device loop0): using free-space-tree
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 0 UID: 0 PID: 5597 Comm: syz.0.15 Not tainted 6.11.0-syzkaller-g98f7e32f20d2 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:btrfs_root_node+0x86/0x3b0 fs/btrfs/ctree.c:260
Code: 20 87 c8 fd 48 83 c4 08 e8 17 6c 12 08 89 c3 31 ff 89 c6 e8 cc 4b ec fd 85 db 74 17 e8 b3 7d d2 fd 84 c0 74 1c e8 7a 47 ec fd <43> 80 3c 3c 00 75 4b eb 51 e8 6c 47 ec fd 43 80 3c 3c 00 75 3d eb
RSP: 0018:ffffc900027e76c0 EFLAGS: 00010293
RAX: ffffffff83a74536 RBX: 0000000000000001 RCX: ffff8880007e4880
RDX: 0000000000000000 RSI: ffffffff8c608f20 RDI: ffffffff8c608ee0
RBP: ffffc900027e78b0 R08: ffffffff83a74524 R09: 1ffffffff283c908
R10: dffffc0000000000 R11: fffffbfff283c909 R12: 0000000000000003
R13: dffffc0000000000 R14: 0000000000000018 R15: dffffc0000000000
FS:  00007f74feb6c6c0(0000) GS:ffff88801fe00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056061eef2000 CR3: 0000000056634000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 btrfs_read_lock_root_node+0x27/0xd0 fs/btrfs/locking.c:279
 btrfs_build_ref_tree+0x112/0x16f0 fs/btrfs/ref-verify.c:1005
 open_ctree+0x1fea/0x2a10 fs/btrfs/disk-io.c:3533
 btrfs_fill_super fs/btrfs/super.c:965 [inline]
 btrfs_get_tree_super fs/btrfs/super.c:1888 [inline]
 btrfs_get_tree+0xe7a/0x1920 fs/btrfs/super.c:2114
 vfs_get_tree+0x90/0x2b0 fs/super.c:1800
 fc_mount+0x1b/0xb0 fs/namespace.c:1231
 btrfs_get_tree_subvol fs/btrfs/super.c:2077 [inline]
 btrfs_get_tree+0x652/0x1920 fs/btrfs/super.c:2115
 vfs_get_tree+0x90/0x2b0 fs/super.c:1800
 do_new_mount+0x2be/0xb40 fs/namespace.c:3472
 do_mount fs/namespace.c:3812 [inline]
 __do_sys_mount fs/namespace.c:4020 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3997
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f74fdd7b65a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f74feb6be68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f74feb6bef0 RCX: 00007f74fdd7b65a
RDX: 0000000020005100 RSI: 0000000020000040 RDI: 00007f74feb6beb0
RBP: 0000000020005100 R08: 00007f74feb6bef0 R09: 0000000000a08811
R10: 0000000000a08811 R11: 0000000000000246 R12: 0000000020000040
R13: 00007f74feb6beb0 R14: 0000000000005112 R15: 0000000020000080
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:btrfs_root_node+0x86/0x3b0 fs/btrfs/ctree.c:260
Code: 20 87 c8 fd 48 83 c4 08 e8 17 6c 12 08 89 c3 31 ff 89 c6 e8 cc 4b ec fd 85 db 74 17 e8 b3 7d d2 fd 84 c0 74 1c e8 7a 47 ec fd <43> 80 3c 3c 00 75 4b eb 51 e8 6c 47 ec fd 43 80 3c 3c 00 75 3d eb
RSP: 0018:ffffc900027e76c0 EFLAGS: 00010293
RAX: ffffffff83a74536 RBX: 0000000000000001 RCX: ffff8880007e4880
RDX: 0000000000000000 RSI: ffffffff8c608f20 RDI: ffffffff8c608ee0
RBP: ffffc900027e78b0 R08: ffffffff83a74524 R09: 1ffffffff283c908
R10: dffffc0000000000 R11: fffffbfff283c909 R12: 0000000000000003
R13: dffffc0000000000 R14: 0000000000000018 R15: dffffc0000000000
FS:  00007f74feb6c6c0(0000) GS:ffff88801fe00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056061eef2000 CR3: 0000000056634000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	87 c8                	xchg   %ecx,%eax
   2:	fd                   	std
   3:	48 83 c4 08          	add    $0x8,%rsp
   7:	e8 17 6c 12 08       	call   0x8126c23
   c:	89 c3                	mov    %eax,%ebx
   e:	31 ff                	xor    %edi,%edi
  10:	89 c6                	mov    %eax,%esi
  12:	e8 cc 4b ec fd       	call   0xfdec4be3
  17:	85 db                	test   %ebx,%ebx
  19:	74 17                	je     0x32
  1b:	e8 b3 7d d2 fd       	call   0xfdd27dd3
  20:	84 c0                	test   %al,%al
  22:	74 1c                	je     0x40
  24:	e8 7a 47 ec fd       	call   0xfdec47a3
* 29:	43 80 3c 3c 00       	cmpb   $0x0,(%r12,%r15,1) <-- trapping instruction
  2e:	75 4b                	jne    0x7b
  30:	eb 51                	jmp    0x83
  32:	e8 6c 47 ec fd       	call   0xfdec47a3
  37:	43 80 3c 3c 00       	cmpb   $0x0,(%r12,%r15,1)
  3c:	75 3d                	jne    0x7b
  3e:	eb                   	.byte 0xeb