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,compression=lz4,nojournal_transaction_names
invalid journal entry, version=1.7: mi_btree_bitmap type=dev_usage in superblock: bad pad, fixing
bcachefs (loop0): recovering from clean shutdown, journal seq 10
bcachefs (loop0): Version upgrade required:
Version upgrade from 0.24: unwritten_extents to 1.7: mi_btree_bitmap incomplete
Doing incompatible version upgrade from 0.24: unwritten_extents to 1.20: directory_size
  running recovery passes: check_allocations,check_alloc_info,check_lrus,check_btree_backpointers,check_backpointers_to_extents,check_extents_to_backpointers,check_alloc_to_lru_refs,bucket_gens_init,check_snapshot_trees,check_snapshots,check_subvols,check_subvol_children,delete_dead_snapshots,check_inodes,check_extents,check_indirect_extents,check_dirents,check_xattrs,check_root,check_unreachable_inodes,check_subvolume_structure,check_directory_structure,check_nlinks,set_fs_needs_rebalance
bcachefs (loop0): error validating btree node on loop0 at btree dirents level 0/0
  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  
  node offset 16/24: btree node data missing: expected 24 sectors, found 16, fixing
bcachefs (loop0): btree_node_read_work: rewriting btree node at due to error
  btree=dirents level=0 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
bcachefs (loop0): error validating btree node at btree alloc level 0/0
  u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq ac62141f8dc7e261 written 24 min_key POS_MIN durability: 1 ptr: 0:26:0 gen 0  
  node offset 8/24 bset u64s 375 bset byte offset 184: keys out of order: u64s 11 type alloc_v4 0:32:0 len 0 ver 0 > u64s 11 type alloc_v4 0:2:0 len 0 ver 0, fixing
invalid bkey in btree_node btree=alloc level=0: u64s 12 type alloc_v4 0:31:0 len 0 ver 0: 
  gen 0 oldest_gen 0 data_type free
  journal_seq_nonempty 4
  journal_seq_empty    0
  need_discard         1
  need_inc_gen         1
  dirty_sectors        0
  stripe_sectors       0
  cached_sectors       212
  stripe               0
  stripe_redundancy    0
  io_time[READ]        1
  io_time[WRITE]       512
  fragmentation     0
  bp_start          8
  invalid data type (got 0 should be 5): delete?, fixing
bcachefs (loop0): btree_node_read_work: rewriting btree node at due to error
  btree=alloc level=0 u64s 11 type btree_ptr_v2 SPOS_MAX len 0 ver 0: seq ac62141f8dc7e261 written 24 min_key POS_MIN durability: 1 ptr: 0:26:0 gen 0
==================================================================
BUG: KASAN: use-after-free in bch2_btree_node_read_done+0x1015/0x5f70 fs/bcachefs/btree_io.c:1083
Read of size 8 at addr ffff8880449e0010 by task syz.0.0/5332

CPU: 0 UID: 0 PID: 5332 Comm: syz.0.0 Not tainted 6.13.0-syzkaller-07267-g405057718a1f #0
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 lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:489
 kasan_report+0x143/0x180 mm/kasan/report.c:602
 bch2_btree_node_read_done+0x1015/0x5f70 fs/bcachefs/btree_io.c:1083
 btree_node_read_work+0x6dc/0x1380 fs/bcachefs/btree_io.c:1358
 bch2_btree_node_read+0x2433/0x29f0
 __bch2_btree_root_read fs/bcachefs/btree_io.c:1789 [inline]
 bch2_btree_root_read+0x617/0x7a0 fs/bcachefs/btree_io.c:1811
 read_btree_roots+0x3d3/0xa70 fs/bcachefs/recovery.c:582
 bch2_fs_recovery+0x260f/0x3de0 fs/bcachefs/recovery.c:929
 bch2_fs_start+0x37c/0x610 fs/bcachefs/super.c:1030
 bch2_fs_get_tree+0xd8d/0x1740 fs/bcachefs/fs.c:2203
 vfs_get_tree+0x90/0x2b0 fs/super.c:1814
 do_new_mount+0x2be/0xb40 fs/namespace.c:3560
 do_mount fs/namespace.c:3900 [inline]
 __do_sys_mount fs/namespace.c:4111 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088
 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: 0033:0x7f1889b8e4ca
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:00007f188a9f6e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f188a9f6ef0 RCX: 00007f1889b8e4ca
RDX: 00000000200000c0 RSI: 000000002009e000 RDI: 00007f188a9f6eb0
RBP: 00000000200000c0 R08: 00007f188a9f6ef0 R09: 0000000000000010
R10: 0000000000000010 R11: 0000000000000246 R12: 000000002009e000
R13: 00007f188a9f6eb0 R14: 000000000000597b R15: 0000000020000480
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x449e0
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
raw: 04fff00000000000 ffffea0001127908 ffff88801fc44ba0 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Reclaimable, gfp_mask 0x452cd0(GFP_KERNEL_ACCOUNT|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_RECLAIMABLE), pid 5332, tgid 5331 (syz.0.0), ts 75536045527, free_ts 75724042086
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1558
 prep_new_page mm/page_alloc.c:1566 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3476
 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4753
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 ___kmalloc_large_node+0x8b/0x1d0 mm/slub.c:4243
 __kmalloc_large_node_noprof+0x1a/0x80 mm/slub.c:4270
 __do_kmalloc_node mm/slub.c:4286 [inline]
 __kmalloc_node_noprof+0x33a/0x4d0 mm/slub.c:4304
 __kvmalloc_node_noprof+0x72/0x190 mm/util.c:645
 btree_node_data_alloc+0xdb/0x260 fs/bcachefs/btree_cache.c:153
 __bch2_btree_node_mem_alloc+0x1d8/0x3e0 fs/bcachefs/btree_cache.c:198
 bch2_fs_btree_cache_init+0x27a/0x630 fs/bcachefs/btree_cache.c:652
 bch2_fs_alloc fs/bcachefs/super.c:908 [inline]
 bch2_fs_open+0x2890/0x2d50 fs/bcachefs/super.c:2053
 bch2_fs_get_tree+0x738/0x1740 fs/bcachefs/fs.c:2190
 vfs_get_tree+0x90/0x2b0 fs/super.c:1814
 do_new_mount+0x2be/0xb40 fs/namespace.c:3560
 do_mount fs/namespace.c:3900 [inline]
 __do_sys_mount fs/namespace.c:4111 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
page last free pid 5332 tgid 5331 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_page+0xd3f/0x1010 mm/page_alloc.c:2659
 __folio_put+0x2b3/0x360 mm/swap.c:112
 folio_put include/linux/mm.h:1489 [inline]
 free_large_kmalloc+0xfe/0x180 mm/slub.c:4732
 kfree+0x212/0x430 mm/slub.c:4755
 btree_bounce_free fs/bcachefs/btree_io.c:111 [inline]
 bch2_btree_node_read_done+0x3b1f/0x5f70 fs/bcachefs/btree_io.c:1243
 btree_node_read_work+0x6dc/0x1380 fs/bcachefs/btree_io.c:1358
 bch2_btree_node_read+0x2433/0x29f0
 __bch2_btree_root_read fs/bcachefs/btree_io.c:1789 [inline]
 bch2_btree_root_read+0x617/0x7a0 fs/bcachefs/btree_io.c:1811
 read_btree_roots+0x3d3/0xa70 fs/bcachefs/recovery.c:582
 bch2_fs_recovery+0x260f/0x3de0 fs/bcachefs/recovery.c:929
 bch2_fs_start+0x37c/0x610 fs/bcachefs/super.c:1030
 bch2_fs_get_tree+0xd8d/0x1740 fs/bcachefs/fs.c:2203
 vfs_get_tree+0x90/0x2b0 fs/super.c:1814
 do_new_mount+0x2be/0xb40 fs/namespace.c:3560
 do_mount fs/namespace.c:3900 [inline]
 __do_sys_mount fs/namespace.c:4111 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83

Memory state around the buggy address:
 ffff8880449dff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880449dff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880449e0000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                         ^
 ffff8880449e0080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880449e0100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================