loop0: detected capacity change from 0 to 32768
bcachefs (loop0): starting version 1.7: mi_btree_bitmap opts=errors=continue,metadata_checksum=none,data_checksum=none,fsck,nochanges,norecovery,nojournal_transaction_names,read_only,nocow
  allowing incompatible features above 0.0: (unknown version)
  features: lz4,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): invalid journal entry, version=1.7: mi_btree_bitmap type=clock in superblock: bad rw, fixing
bcachefs (loop0): invalid bkey in superblock btree=xattrs level=0: u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq 2285c34bed0abe32 written 16 min_key POS_MIN durability: 0 crc: c_size 1 size 1 offset 0 nonce 0 csum none 12010b:10004000b  compress none
  invalid key type for btree xattrs (btree_ptr_v2), deleting
bcachefs (loop0): recovering from clean shutdown, journal seq 10
bcachefs (loop0): Version upgrade from 1.3: rebalance_work to 1.7: mi_btree_bitmap incomplete
Doing compatible version upgrade from 1.3: rebalance_work to 1.28: inode_has_case_insensitive
  running recovery passes: check_allocations,check_extents_to_backpointers,check_subvols,check_inodes,check_dirents
bcachefs (loop0): invalid bkey in btree_node btree=inodes level=0: u64s 17 type inode_v3 0:4097:U32_MAX len 0 ver 0: (unpack error)
  invalid variable length fields, deleting
bcachefs (loop0): btree node read error at btree dirents level 0/0
  u64s 11 type btree_ptr_v2 9223372036854775807:U64_MAX:U32_MAX len 0 ver 0: seq 9aa2895aefce4bdf written 24 min_key POS_MIN durability: 1 ptr: 0:41:0 gen 0
  loop0 node offset 0/24 bset u64s 0: incorrect max key SPOS_MAX
  flagging btree dirents lost data
  running recovery pass check_lrus (14), currently at recovery_pass_empty (0)
  running recovery pass check_backpointers_to_extents (16), currently at recovery_pass_empty (0)
  running recovery pass scan_for_btree_nodes (1), currently at recovery_pass_empty (0)
  ret btree_node_read_validate_error
bcachefs (loop0): error reading btree root btree=dirents level=0: btree_node_read_error, fixing
bcachefs (loop0): error reading btree root btree=alloc level=0: btree_node_read_error, fixing
bcachefs (loop0): scan_for_btree_nodes...
bcachefs (loop0): btree node scan found 6 nodes after overwrites
 done
bcachefs (loop0): check_topology...
bcachefs (loop0): btree root dirents unreadable, must recover from scan
bcachefs (loop0): bch2_get_scanned_nodes(): recovery btree=dirents 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 9aa2895aefce4bdf written 24 min_key POS_MIN durability: 1 ptr: 0:41:0 gen 0
 done
bcachefs (loop0): accounting_read... done
bcachefs (loop0): alloc_read... done
bcachefs (loop0): snapshots_read... done
bcachefs (loop0): Fixed errors, running fsck a second time to verify fs is clean
bcachefs (loop0): scanning for old btree nodes: min_version 0.11: inode_btree_change
bcachefs (loop0): going read-write
bcachefs (loop0): insufficient writeable journal devices available: have 0, need 1
rw journal devs: loop0
------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in fs/bcachefs/sb-downgrade.c:276:4
index 0 is out of range for type '__le16[] __counted_by(nr_errors)' (aka 'unsigned short[]')
CPU: 0 UID: 0 PID: 5326 Comm: syz.0.0 Not tainted 6.15.0-syzkaller-13743-g8630c59e9936 #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
 downgrade_table_extra fs/bcachefs/sb-downgrade.c:276 [inline]
 bch2_sb_downgrade_update+0xb69/0xf00 fs/bcachefs/sb-downgrade.c:399
 bch2_write_super+0xc24/0x2d30 fs/bcachefs/super-io.c:1081
 bch2_scan_old_btree_nodes+0x18a/0x240 fs/bcachefs/move.c:1275
 bch2_fs_recovery+0x340d/0x39a0 fs/bcachefs/recovery.c:1086
 bch2_fs_start+0xa99/0xd90 fs/bcachefs/super.c:1200
 bch2_fs_get_tree+0xb6c/0x1460 fs/bcachefs/fs.c:2489
 vfs_get_tree+0x8f/0x2b0 fs/super.c:1802
 do_new_mount+0x24a/0xa40 fs/namespace.c:3856
 do_mount fs/namespace.c:4193 [inline]
 __do_sys_mount fs/namespace.c:4404 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4381
 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: 0033:0x7f69ae3900ca
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:00007f69af22be68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f69af22bef0 RCX: 00007f69ae3900ca
RDX: 00002000000000c0 RSI: 0000200000000080 RDI: 00007f69af22beb0
RBP: 00002000000000c0 R08: 00007f69af22bef0 R09: 0000000000818001
R10: 0000000000818001 R11: 0000000000000246 R12: 0000200000000080
R13: 00007f69af22beb0 R14: 0000000000005970 R15: 0000200000000180
 </TASK>
---[ end trace ]---