loop0: detected capacity change from 0 to 16384
=======================================================
WARNING: The mand mount option has been deprecated and
         and is ignored by this kernel. Remove the mand
         option from the mount to silence this warning.
=======================================================
bcachefs (loop0): starting version 1.13: inode_has_child_snapshots opts=metadata_checksum=none,data_checksum=none,read_only
  features: new_siphash,inline_data,new_extent_overwrite,btree_ptr_v2,new_varint,journal_no_flush,alloc_v2,extents_across_btree_nodes
bcachefs (loop0): Using encoding defined by superblock: utf8-12.1.0
bcachefs (loop0): recovering from clean shutdown, journal seq 15
bcachefs (loop0): Doing compatible version upgrade from 1.13: inode_has_child_snapshots to 1.28: inode_has_case_insensitive
  running recovery passes: check_allocations,check_extents_to_backpointers,check_inodes
bcachefs (loop0): invalid bkey in btree_node btree=backpointers level=0: u64s 9 type backpointer 0:0:2006864055 len 0 ver 0: bucket=0:0:0 btree=alloc level=1 data_type=btree suboffset=0 len=32 gen=0 pos=0:82:0
  nonzero snapshot, deleting
bcachefs (loop0): error reading btree root btree=backpointers level=0: btree_node_read_error, fixing
------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in fs/bcachefs/disk_accounting.c:238:2
index 40 is out of range for type 'const unsigned int[9]'
CPU: 0 UID: 0 PID: 5355 Comm: syz.0.0 Not tainted syzkaller #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
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 ubsan_epilogue+0xa/0x40 lib/ubsan.c:233
 __ubsan_handle_out_of_bounds+0xe9/0xf0 lib/ubsan.c:455
 bch2_accounting_validate+0x112f/0x1400 fs/bcachefs/disk_accounting.c:238
 bch2_bkey_val_validate+0x202/0x3e0 fs/bcachefs/bkey_methods.c:143
 btree_node_bkey_val_validate fs/bcachefs/btree_io.c:880 [inline]
 bch2_btree_node_read_done+0x4051/0x5550 fs/bcachefs/btree_io.c:1303
 btree_node_read_work+0x40e/0xe60 fs/bcachefs/btree_io.c:1440
 bch2_btree_node_read+0x887/0x2a00 fs/bcachefs/btree_io.c:-1
 __bch2_btree_root_read fs/bcachefs/btree_io.c:1906 [inline]
 bch2_btree_root_read+0x5f0/0x760 fs/bcachefs/btree_io.c:1928
 read_btree_roots+0x2c6/0x840 fs/bcachefs/recovery.c:615
 bch2_fs_recovery+0x261f/0x3a50 fs/bcachefs/recovery.c:1006
 bch2_fs_start+0xaaf/0xda0 fs/bcachefs/super.c:1213
 bch2_fs_get_tree+0xb39/0x1520 fs/bcachefs/fs.c:2488
 vfs_get_tree+0x8f/0x2b0 fs/super.c:1815
 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808
 do_mount fs/namespace.c:4136 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4324
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4f4599038a
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:00007f4f468bde68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f4f468bdef0 RCX: 00007f4f4599038a
RDX: 0000200000004900 RSI: 0000200000004940 RDI: 00007f4f468bdeb0
RBP: 0000200000004900 R08: 00007f4f468bdef0 R09: 0000000000200041
R10: 0000000000200041 R11: 0000000000000246 R12: 0000200000004940
R13: 00007f4f468bdeb0 R14: 000000000000499f R15: 0000200000000100
 </TASK>
---[ end trace ]---