BTRFS info (device loop0 state MCS): disabling free space tree
BTRFS info (device loop0 state MCS): clearing compat-ro feature flag for FREE_SPACE_TREE (0x1)
BTRFS info (device loop0 state MCS): clearing compat-ro feature flag for FREE_SPACE_TREE_VALID (0x2)
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: 5558 Comm: syz.0.15 Not tainted 6.12.0-rc2-syzkaller-g8cf0b93919e1 #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:backup_super_roots fs/btrfs/disk-io.c:1690 [inline]
RIP: 0010:write_all_supers+0x97a/0x40f0 fs/btrfs/disk-io.c:4031
Code: 00 00 00 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 8a 34 00 00 44 88 33 48 8b 5c 24 10 48 83 c3 18 49 89 df 49 c1 ef 03 <43> 80 3c 2f 00 74 08 48 89 df e8 57 5f 49 fe 48 89 5c 24 10 48 8b
RSP: 0018:ffffc900023af040 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 0000000000000018 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff8880364e5a80
RBP: ffffc900023af3f0 R08: ffff88803f97406b R09: 1ffff11007f2e80d
R10: dffffc0000000000 R11: ffffed1007f2e80e R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000003
FS:  00007f99316056c0(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056516a90d000 CR3: 000000003b3fe000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 btrfs_commit_transaction+0x1eae/0x3740 fs/btrfs/transaction.c:2529
 btrfs_delete_free_space_tree+0x383/0x730 fs/btrfs/free-space-tree.c:1312
 btrfs_start_pre_rw_mount+0xf28/0x1300 fs/btrfs/disk-io.c:3011
 btrfs_remount_rw fs/btrfs/super.c:1309 [inline]
 btrfs_reconfigure+0xae6/0x2d40 fs/btrfs/super.c:1534
 btrfs_reconfigure_for_mount fs/btrfs/super.c:2020 [inline]
 btrfs_get_tree_subvol fs/btrfs/super.c:2079 [inline]
 btrfs_get_tree+0x918/0x1920 fs/btrfs/super.c:2115
 vfs_get_tree+0x90/0x2b0 fs/super.c:1800
 do_new_mount+0x2be/0xb40 fs/namespace.c:3507
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4055 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4032
 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: 0033:0x7f993077cef9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007f9931605038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f9930935f80 RCX: 00007f993077cef9
RDX: 0000000020000280 RSI: 0000000020000180 RDI: 0000000020000100
RBP: 00007f99307ef01e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9930935f80 R15: 00007ffe0cf51808
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:backup_super_roots fs/btrfs/disk-io.c:1690 [inline]
RIP: 0010:write_all_supers+0x97a/0x40f0 fs/btrfs/disk-io.c:4031
Code: 00 00 00 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 8a 34 00 00 44 88 33 48 8b 5c 24 10 48 83 c3 18 49 89 df 49 c1 ef 03 <43> 80 3c 2f 00 74 08 48 89 df e8 57 5f 49 fe 48 89 5c 24 10 48 8b
RSP: 0018:ffffc900023af040 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 0000000000000018 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff8880364e5a80
RBP: ffffc900023af3f0 R08: ffff88803f97406b R09: 1ffff11007f2e80d
R10: dffffc0000000000 R11: ffffed1007f2e80e R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000003
FS:  00007f99316056c0(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005630189b1b40 CR3: 000000003b3fe000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	00 48 89             	add    %cl,-0x77(%rax)
   5:	d8 48 c1             	fmuls  -0x3f(%rax)
   8:	e8 03 42 0f b6       	call   0xb60f4210
   d:	04 28                	add    $0x28,%al
   f:	84 c0                	test   %al,%al
  11:	0f 85 8a 34 00 00    	jne    0x34a1
  17:	44 88 33             	mov    %r14b,(%rbx)
  1a:	48 8b 5c 24 10       	mov    0x10(%rsp),%rbx
  1f:	48 83 c3 18          	add    $0x18,%rbx
  23:	49 89 df             	mov    %rbx,%r15
  26:	49 c1 ef 03          	shr    $0x3,%r15
* 2a:	43 80 3c 2f 00       	cmpb   $0x0,(%r15,%r13,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 57 5f 49 fe       	call   0xfe495f90
  39:	48 89 5c 24 10       	mov    %rbx,0x10(%rsp)
  3e:	48                   	rex.W
  3f:	8b                   	.byte 0x8b