general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 4908 Comm: syz.4.113 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:btrfs_root_node+0x4f/0x350 fs/btrfs/ctree.c:132
Code: 80 2e fe e8 c3 56 01 00 e8 8e 11 6c 06 89 c5 31 ff 89 c6 e8 f3 f3 41 fe 85 ed 74 17 e8 aa d5 2d fe 84 c0 74 1c e8 81 f0 41 fe <42> 80 3c 23 00 75 4b eb 51 e8 73 f0 41 fe 42 80 3c 23 00 75 3d eb
RSP: 0018:ffffc9000329f588 EFLAGS: 00010283
RAX: ffffffff8335db8f RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc90010b0f000 RSI: 000000000001f393 RDI: 000000000001f394
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff1ff5419
R10: fffffbfff1ff5419 R11: 1ffffffff1ff5418 R12: dffffc0000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000
FS:  00007ff8b62ad6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000001fa4b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 btrfs_read_lock_root_node+0x75/0x390 fs/btrfs/locking.c:276
 btrfs_build_ref_tree+0x133/0x1180 fs/btrfs/ref-verify.c:993
 open_ctree+0x26dd/0x3250 fs/btrfs/disk-io.c:3609
 btrfs_fill_super+0x1c2/0x2e0 fs/btrfs/super.c:1387
 btrfs_mount_root+0x857/0x8c0 fs/btrfs/super.c:1751
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 fc_mount fs/namespace.c:1005 [inline]
 vfs_kern_mount+0xba/0x150 fs/namespace.c:1035
 btrfs_mount+0x2d7/0xa50 fs/btrfs/super.c:1811
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7ff8b8089eea
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:00007ff8b62ace68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ff8b62acef0 RCX: 00007ff8b8089eea
RDX: 0000200000000000 RSI: 0000200000000040 RDI: 00007ff8b62aceb0
RBP: 0000200000000000 R08: 00007ff8b62acef0 R09: 000000000001c005
R10: 000000000001c005 R11: 0000000000000246 R12: 0000200000000040
R13: 00007ff8b62aceb0 R14: 00000000000055ae R15: 0000200000000840
 </TASK>
Modules linked in:
---[ end trace f958826c4c9af18a ]---
RIP: 0010:btrfs_root_node+0x4f/0x350 fs/btrfs/ctree.c:132
Code: 80 2e fe e8 c3 56 01 00 e8 8e 11 6c 06 89 c5 31 ff 89 c6 e8 f3 f3 41 fe 85 ed 74 17 e8 aa d5 2d fe 84 c0 74 1c e8 81 f0 41 fe <42> 80 3c 23 00 75 4b eb 51 e8 73 f0 41 fe 42 80 3c 23 00 75 3d eb
RSP: 0018:ffffc9000329f588 EFLAGS: 00010283
RAX: ffffffff8335db8f RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc90010b0f000 RSI: 000000000001f393 RDI: 000000000001f394
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff1ff5419
R10: fffffbfff1ff5419 R11: 1ffffffff1ff5418 R12: dffffc0000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000
FS:  00007ff8b62ad6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000001fa4b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	80 2e fe             	subb   $0xfe,(%rsi)
   3:	e8 c3 56 01 00       	call   0x156cb
   8:	e8 8e 11 6c 06       	call   0x66c119b
   d:	89 c5                	mov    %eax,%ebp
   f:	31 ff                	xor    %edi,%edi
  11:	89 c6                	mov    %eax,%esi
  13:	e8 f3 f3 41 fe       	call   0xfe41f40b
  18:	85 ed                	test   %ebp,%ebp
  1a:	74 17                	je     0x33
  1c:	e8 aa d5 2d fe       	call   0xfe2dd5cb
  21:	84 c0                	test   %al,%al
  23:	74 1c                	je     0x41
  25:	e8 81 f0 41 fe       	call   0xfe41f0ab
* 2a:	42 80 3c 23 00       	cmpb   $0x0,(%rbx,%r12,1) <-- trapping instruction
  2f:	75 4b                	jne    0x7c
  31:	eb 51                	jmp    0x84
  33:	e8 73 f0 41 fe       	call   0xfe41f0ab
  38:	42 80 3c 23 00       	cmpb   $0x0,(%rbx,%r12,1)
  3d:	75 3d                	jne    0x7c
  3f:	eb                   	.byte 0xeb