u64s 7 type inline_data 536870912:8:U32_MAX len 8 ver 0: datalen 16: 73797a6b616c6c657273000000000000, fixing
key in missing inode:
  u64s 7 type extent 536870913:24:U32_MAX len 24 ver 0: durability: 1 crc: c_size 8 size 24 offset 0 nonce 0 csum none 0:0  compress lz4 ptr: 0:34:8 gen 0, fixing
==================================================================
BUG: KASAN: use-after-free in __extent_entry_type fs/bcachefs/extents.h:53 [inline]
BUG: KASAN: use-after-free in extent_entry_is_crc fs/bcachefs/extents.h:120 [inline]
BUG: KASAN: use-after-free in check_extent_overbig+0x27b/0x7d0 fs/bcachefs/fsck.c:1921
Read of size 8 at addr ffff8880577c0188 by task syz.6.933/11715

CPU: 0 UID: 0 PID: 11715 Comm: syz.6.933 Not tainted 6.13.0-rc1-next-20241205-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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
 __extent_entry_type fs/bcachefs/extents.h:53 [inline]
 extent_entry_is_crc fs/bcachefs/extents.h:120 [inline]
 check_extent_overbig+0x27b/0x7d0 fs/bcachefs/fsck.c:1921
 bch2_check_extents+0xa23/0x65a0 fs/bcachefs/fsck.c:2054
 bch2_run_recovery_pass+0xf0/0x1e0 fs/bcachefs/recovery_passes.c:222
 bch2_run_recovery_passes+0x2da/0xaf0 fs/bcachefs/recovery_passes.c:287
 bch2_fs_recovery+0x2660/0x3ab0 fs/bcachefs/recovery.c:917
 bch2_fs_start+0x37c/0x610 fs/bcachefs/super.c:1037
 bch2_fs_get_tree+0xd8d/0x1740 fs/bcachefs/fs.c:2201
 vfs_get_tree+0x90/0x2b0 fs/super.c:1814
 do_new_mount+0x2be/0xb40 fs/namespace.c:3507
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4034
 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: 0033:0x7fe7cf78167a
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:00007fe7d04fae88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fe7d04faf10 RCX: 00007fe7cf78167a
RDX: 00000000200000c0 RSI: 0000000020000000 RDI: 00007fe7d04faed0
RBP: 00000000200000c0 R08: 00007fe7d04faf10 R09: 0000000000800000
R10: 0000000000800000 R11: 0000000000000246 R12: 0000000020000000
R13: 00007fe7d04faed0 R14: 0000000000005991 R15: 00000000200001c0
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880577c6000 pfn:0x577c0
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f0(buddy)
raw: 00fff00000000000 ffffea0001a73808 ffff88813fffc008 0000000000000000
raw: ffff8880577c6000 0000000000000005 00000000f0000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 5, migratetype Unmovable, gfp_mask 0x52800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP), pid 11715, tgid 11710 (syz.6.933), ts 562838193279, free_ts 568452123955
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1549
 prep_new_page mm/page_alloc.c:1557 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3475
 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4752
 __alloc_pages_noprof+0xa/0x30 mm/page_alloc.c:4786
 __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:4228
 __kmalloc_large_node_noprof+0x1a/0x80 mm/slub.c:4255
 __do_kmalloc_node mm/slub.c:4271 [inline]
 __kmalloc_node_noprof+0x33a/0x4d0 mm/slub.c:4289
 __kvmalloc_node_noprof+0x72/0x190 mm/util.c:650
 btree_bounce_alloc fs/bcachefs/btree_io.c:123 [inline]
 bch2_btree_node_read_done+0x3523/0x5c00 fs/bcachefs/btree_io.c:1222
 btree_node_read_work+0x671/0x1230 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+0x441/0xab0 fs/bcachefs/recovery.c:586
 bch2_fs_recovery+0x2615/0x3ab0 fs/bcachefs/recovery.c:909
 bch2_fs_start+0x37c/0x610 fs/bcachefs/super.c:1037
 bch2_fs_get_tree+0xd8d/0x1740 fs/bcachefs/fs.c:2201
page last free pid 11715 tgid 11710 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 __free_pages_ok+0xbbf/0xe40 mm/page_alloc.c:1269
 __folio_put+0x2b3/0x360 mm/swap.c:112
 folio_put include/linux/mm.h:1488 [inline]
 free_large_kmalloc+0xfe/0x180 mm/slub.c:4717
 kfree+0x212/0x430 mm/slub.c:4740
 btree_bounce_free fs/bcachefs/btree_io.c:111 [inline]
 btree_node_sort+0x1100/0x1830 fs/bcachefs/btree_io.c:379
 bch2_btree_post_write_cleanup+0x11a/0xa70 fs/bcachefs/btree_io.c:2293
 bch2_btree_node_prep_for_write+0x55b/0x8f0 fs/bcachefs/btree_trans_commit.c:93
 bch2_trans_lock_write+0x68e/0xc60 fs/bcachefs/btree_trans_commit.c:129
 do_bch2_trans_commit fs/bcachefs/btree_trans_commit.c:877 [inline]
 __bch2_trans_commit+0x2804/0x97c0 fs/bcachefs/btree_trans_commit.c:1081
 bch2_trans_commit fs/bcachefs/btree_update.h:182 [inline]
 check_extent fs/bcachefs/fsck.c:2011 [inline]
 bch2_check_extents+0x4579/0x65a0 fs/bcachefs/fsck.c:2054
 bch2_run_recovery_pass+0xf0/0x1e0 fs/bcachefs/recovery_passes.c:222
 bch2_run_recovery_passes+0x2da/0xaf0 fs/bcachefs/recovery_passes.c:287
 bch2_fs_recovery+0x2660/0x3ab0 fs/bcachefs/recovery.c:917
 bch2_fs_start+0x37c/0x610 fs/bcachefs/super.c:1037
 bch2_fs_get_tree+0xd8d/0x1740 fs/bcachefs/fs.c:2201
 vfs_get_tree+0x90/0x2b0 fs/super.c:1814

Memory state around the buggy address:
 ffff8880577c0080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880577c0100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880577c0180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                      ^
 ffff8880577c0200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880577c0280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================