max: SPOS_MAX, btree topology error: 
bcachefs (loop0): flagging btree snapshots lost data
bcachefs (loop0): error reading btree root btree=snapshots level=0: btree_node_read_error, fixing
bcachefs (loop0): bcachefs (loop0): error validating btree node on loop0 at btree lru level 0/0
  u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq 28f61e078e70b95c written 16 min_key POS_MIN durability: 1 ptr: 0:28:0 gen 0
  node offset 8/16 bset u64s 3: checksum error, type none: got  should be , fixing
bcachefs (loop0): btree_node_read_work: rewriting btree node at due to error
  btree=lru level=0 u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq 28f61e078e70b95c written 16 min_key POS_MIN durability: 1 ptr: 0:28:0 gen 0
bcachefs (loop0): bcachefs (loop0): error validating btree node at btree freespace level 0/0
  u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq e81e1ed936acf3df written 32 min_key POS_MIN durability: 1 ptr: 0:29:0 gen 0
  node offset 0/32 bset u64s 0: bset version 9 older than superblock version_min 24, fixing
bcachefs (loop0): invalid bkey in btree_node btree=freespace level=0: u64s 5 type set 0:120:0 len 0 ver 0
  size == 0, deleting
bcachefs (loop0): flagging btree freespace lost data
bcachefs (loop0): error reading btree root btree=freespace level=0: btree_node_read_error, fixing
bcachefs (loop0): invalid bkey in btree_node btree=backpointers level=0: u64s 9 type inode 0:8921088:0 len 0 ver 0: (unpack error)
  invalid str hash type (9 >= 4), deleting
bcachefs (loop0): bcachefs (loop0): error validating btree node on loop0 at btree deleted_inodes level 0/0
  u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq 1db8f60c84bb244c written 8 min_key POS_MIN durability: 1 ptr: 0:42:0 gen 0
  node offset 0/8 bset u64s 0: invalid bkey format: incorrect key_u64s: got 0, should be 3
  u64s 0 fields 64:0, 64:0, 32:0, 0:0, 0:0, 0:0, btree topology error: 
bcachefs (loop0): flagging btree deleted_inodes lost data
bcachefs (loop0): error reading btree root btree=deleted_inodes level=0: btree_node_read_error, fixing
bcachefs (loop0): scan_for_btree_nodes...
bcachefs (loop0): btree node scan found 2 nodes after overwrites
 done
bcachefs (loop0): check_topology...
bcachefs (loop0): btree root extents unreadable, must recover from scan
bcachefs (loop0): bch2_get_scanned_nodes(): recovery btree=extents level=0 POS_MIN - SPOS_MAX
bcachefs (loop0): bch2_get_scanned_nodes(): recovering u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq c6c25c03258c59c5 written 16 min_key 0:0:U32_MAX durability: 1 ptr: 0:27:0 gen 0
bcachefs (loop0): bch2_get_scanned_nodes(): recovery btree=extents level=0 POS_MIN - 0:0:4294967294
bcachefs (loop0): btree node with incorrect min_key  at btree=extents level=1:
  parent: u64s 5 type btree_ptr SPOS_MAX len 0 ver 0
  next: u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq c6c25c03258c59c5 written 16 min_key 0:0:U32_MAX durability: 1 ptr: 0:27:0 gen 0, fixing
bcachefs (loop0): set_node_min(): u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq c6c25c03258c59c5 written 16 min_key 0:0:U32_MAX durability: 1 ptr: 0:27:0 gen 0 -> POS_MIN
bcachefs (loop0): btree root dirents unreadable, must recover from scan
bcachefs (loop0): no nodes found for btree dirents, continuing
bcachefs (loop0): btree root snapshots unreadable, must recover from scan
bcachefs (loop0): no nodes found for btree snapshots, continuing
bcachefs (loop0): btree root deleted_inodes unreadable, must recover from scan
bcachefs (loop0): no nodes found for btree deleted_inodes, continuing
 done
bcachefs (loop0): accounting_read... done
bcachefs (loop0): alloc_read... done
bcachefs (loop0): snapshots_read...
bcachefs (loop0): running explicit recovery pass reconstruct_snapshots (21), currently at snapshots_read (7)
 done
bcachefs (loop0): check_allocations...
bcachefs (loop0): bucket 0:27 data type btree ptr gen 0 missing in alloc btree
  while marking u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq c6c25c03258c59c5 written 16 min_key R POS_MIN durability: 1 ptr: 0:27:0 gen 0, fixing
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 0 UID: 0 PID: 5323 Comm: syz.0.0 Not tainted 6.15.0-rc1-syzkaller-00288-ge618ee89561b #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:bch2_snapshot_tree_oldest_subvol+0x1d3/0x6a0 fs/bcachefs/snapshot.c:400
Code: e6 e8 d1 c7 36 fd 4c 39 e5 0f 86 c9 03 00 00 e8 63 c5 36 fd 49 6b c4 38 49 01 c6 49 83 c6 18 49 83 c6 20 4c 89 f0 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 c6 03 00 00 41 8b 2e 31 ff 89 ee e8 74
RSP: 0018:ffffc9000d656040 EFLAGS: 00010202
RAX: 0000000000000004 RBX: 0000000000000001 RCX: 0000000000100000
RDX: ffffc9000e082000 RSI: 00000000000a0c2c RDI: 00000000000a0c2d
RBP: ffffffff848c8e3b R08: ffffffff848c8f69 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 00000000ffeb487f
R13: dffffc0000000000 R14: 0000000000000020 R15: 000000000014b780
FS:  00007f2665e756c0(0000) GS:ffff88808c594000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f63f95f028 CR3: 0000000044092000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 bch2_inum_snap_offset_err_msg_trans+0x374/0x680 fs/bcachefs/error.c:694
 bch2_indirect_extent_missing_error+0x411/0x1290 fs/bcachefs/reflink.c:192
 gc_trigger_reflink_p_segment fs/bcachefs/reflink.c:392 [inline]
 __trigger_reflink_p+0x1960/0x1cb0 fs/bcachefs/reflink.c:432
 bch2_trigger_reflink_p+0x299/0x380 fs/bcachefs/reflink.c:451
 bch2_key_trigger fs/bcachefs/bkey_methods.h:88 [inline]
 bch2_gc_mark_key+0x6b9/0x1170 fs/bcachefs/btree_gc.c:639
 bch2_gc_btree fs/bcachefs/btree_gc.c:677 [inline]
 bch2_gc_btrees fs/bcachefs/btree_gc.c:740 [inline]
 bch2_check_allocations+0x1439/0x6930 fs/bcachefs/btree_gc.c:1042
 bch2_run_recovery_pass+0xf0/0x1e0 fs/bcachefs/recovery_passes.c:226
 bch2_run_recovery_passes+0x2ad/0xa90 fs/bcachefs/recovery_passes.c:285
 bch2_fs_recovery+0x292a/0x3e20 fs/bcachefs/recovery.c:936
 bch2_fs_start+0x310/0x620 fs/bcachefs/super.c:1059
 bch2_fs_get_tree+0x113e/0x18f0 fs/bcachefs/fs.c:2253
 vfs_get_tree+0x90/0x2b0 fs/super.c:1759
 do_new_mount+0x2cf/0xb70 fs/namespace.c:3879
 do_mount fs/namespace.c:4219 [inline]
 __do_sys_mount fs/namespace.c:4430 [inline]
 __se_sys_mount+0x38c/0x400 fs/namespace.c:4407
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2664f8e90a
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:00007f2665e74e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f2665e74ef0 RCX: 00007f2664f8e90a
RDX: 0000200000000000 RSI: 0000200000005900 RDI: 00007f2665e74eb0
RBP: 0000200000000000 R08: 00007f2665e74ef0 R09: 0000000000000002
R10: 0000000000000002 R11: 0000000000000246 R12: 0000200000005900
R13: 00007f2665e74eb0 R14: 0000000000005a60 R15: 0000200000000080
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:bch2_snapshot_tree_oldest_subvol+0x1d3/0x6a0 fs/bcachefs/snapshot.c:400
Code: e6 e8 d1 c7 36 fd 4c 39 e5 0f 86 c9 03 00 00 e8 63 c5 36 fd 49 6b c4 38 49 01 c6 49 83 c6 18 49 83 c6 20 4c 89 f0 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 c6 03 00 00 41 8b 2e 31 ff 89 ee e8 74
RSP: 0018:ffffc9000d656040 EFLAGS: 00010202
RAX: 0000000000000004 RBX: 0000000000000001 RCX: 0000000000100000
RDX: ffffc9000e082000 RSI: 00000000000a0c2c RDI: 00000000000a0c2d
RBP: ffffffff848c8e3b R08: ffffffff848c8f69 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 00000000ffeb487f
R13: dffffc0000000000 R14: 0000000000000020 R15: 000000000014b780
FS:  00007f2665e756c0(0000) GS:ffff88808c594000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f63f95f028 CR3: 0000000044092000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	e6 e8                	out    %al,$0xe8
   2:	d1 c7                	rol    %edi
   4:	36 fd                	ss std
   6:	4c 39 e5             	cmp    %r12,%rbp
   9:	0f 86 c9 03 00 00    	jbe    0x3d8
   f:	e8 63 c5 36 fd       	call   0xfd36c577
  14:	49 6b c4 38          	imul   $0x38,%r12,%rax
  18:	49 01 c6             	add    %rax,%r14
  1b:	49 83 c6 18          	add    $0x18,%r14
  1f:	49 83 c6 20          	add    $0x20,%r14
  23:	4c 89 f0             	mov    %r14,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 c6 03 00 00    	jne    0x3fd
  37:	41 8b 2e             	mov    (%r14),%ebp
  3a:	31 ff                	xor    %edi,%edi
  3c:	89 ee                	mov    %ebp,%esi
  3e:	e8                   	.byte 0xe8
  3f:	74                   	.byte 0x74