general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 1 PID: 6688 Comm: syz.0.16 Not tainted 6.6.100-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:backup_super_roots fs/btrfs/disk-io.c:1668 [inline]
RIP: 0010:write_all_supers+0x8a7/0x3e60 fs/btrfs/disk-io.c:4079
Code: 10 48 8d 9a 9a 00 00 00 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 53 33 00 00 44 88 33 49 83 c4 18 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 0d 4c 89 e7 e8 5a 5b 67 fe 48 8b 54 24 10 49 8b
RSP: 0018:ffffc900037e7400 EFLAGS: 00010206
RAX: 0000000000000003 RBX: ffff88804c9eabc5 RCX: 0000000000000000
RDX: ffff88804c9eab2b RSI: 0000000000000004 RDI: ffff888075351910
RBP: ffffc900037e77b0 R08: ffff888061ba8063 R09: 1ffff1100c37500c
R10: dffffc0000000000 R11: ffffed100c37500d R12: 0000000000000018
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff88804bc5a018
FS:  00007f8c745d06c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d7a971f950 CR3: 0000000022ecf000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 btrfs_commit_transaction+0x1e95/0x3760 fs/btrfs/transaction.c:2516
 btrfs_set_free_space_cache_v1_active+0x71/0x1c0 fs/btrfs/free-space-cache.c:4151
 btrfs_remount_cleanup fs/btrfs/super.c:1684 [inline]
 btrfs_remount+0xfd1/0x1470 fs/btrfs/super.c:1861
 reconfigure_super+0x21e/0x880 fs/super.c:1151
 do_remount fs/namespace.c:2905 [inline]
 path_mount+0xd19/0xfe0 fs/namespace.c:3690
 do_mount fs/namespace.c:3711 [inline]
 __do_sys_mount fs/namespace.c:3920 [inline]
 __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3897
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8c7379014a
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:00007f8c745cfe68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f8c745cfef0 RCX: 00007f8c7379014a
RDX: 0000200000000180 RSI: 0000200000000380 RDI: 0000000000000000
RBP: 0000200000000180 R08: 00007f8c745cfef0 R09: 0000000002042023
R10: 0000000002042023 R11: 0000000000000246 R12: 0000200000000380
R13: 00007f8c745cfeb0 R14: 0000000000000000 R15: 00002000000002c0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:backup_super_roots fs/btrfs/disk-io.c:1668 [inline]
RIP: 0010:write_all_supers+0x8a7/0x3e60 fs/btrfs/disk-io.c:4079
Code: 10 48 8d 9a 9a 00 00 00 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 53 33 00 00 44 88 33 49 83 c4 18 4c 89 e0 48 c1 e8 03 <42> 80 3c 28 00 74 0d 4c 89 e7 e8 5a 5b 67 fe 48 8b 54 24 10 49 8b
RSP: 0018:ffffc900037e7400 EFLAGS: 00010206
RAX: 0000000000000003 RBX: ffff88804c9eabc5 RCX: 0000000000000000
RDX: ffff88804c9eab2b RSI: 0000000000000004 RDI: ffff888075351910
RBP: ffffc900037e77b0 R08: ffff888061ba8063 R09: 1ffff1100c37500c
R10: dffffc0000000000 R11: ffffed100c37500d R12: 0000000000000018
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff88804bc5a018
FS:  00007f8c745d06c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d7a971f950 CR3: 0000000022ecf000 CR4: 00000000003506e0
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	48 8d 9a 9a 00 00 00 	lea    0x9a(%rdx),%rbx
   7:	48 89 d8             	mov    %rbx,%rax
   a:	48 c1 e8 03          	shr    $0x3,%rax
   e:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax
  13:	84 c0                	test   %al,%al
  15:	0f 85 53 33 00 00    	jne    0x336e
  1b:	44 88 33             	mov    %r14b,(%rbx)
  1e:	49 83 c4 18          	add    $0x18,%r12
  22:	4c 89 e0             	mov    %r12,%rax
  25:	48 c1 e8 03          	shr    $0x3,%rax
* 29:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2e:	74 0d                	je     0x3d
  30:	4c 89 e7             	mov    %r12,%rdi
  33:	e8 5a 5b 67 fe       	call   0xfe675b92
  38:	48 8b 54 24 10       	mov    0x10(%rsp),%rdx
  3d:	49                   	rex.WB
  3e:	8b                   	.byte 0x8b