u64s 7 type dirent 4096:1293609634568567736:U32_MAX len 0 ver 0: file3 -> 1073741825 type reg, fixing
bcachefs (loop0): directory with missing backpointer
  u64s 7 type dirent 4096:2274629672097255523:U32_MAX len 0 ver 0: file0 -> 4098 type dir
  inum: 4098:4294967295 
    mode=40600
    flags=(4300000)
    journal_seq=25
    hash_seed=3b7f0bf53ab1d8b1
    hash_type=siphash
    bi_size=0
    bi_sectors=0
    bi_version=0
    bi_atime=35230771152728332
    bi_ctime=35230771152728332
    bi_mtime=35230771152728332
    bi_otime=35230771152728332
    bi_uid=0
    bi_gid=0
    bi_nlink=0
    bi_generation=0
    bi_dev=0
    bi_data_checksum=0
    bi_compression=0
    bi_project=0
    bi_background_compression=0
    bi_data_replicas=0
    bi_promote_target=0
    bi_foreground_target=0
    bi_background_target=0
    bi_erasure_code=0
    bi_fields_set=0
    bi_dir=0
    bi_dir_offset=0
    bi_subvol=0
    bi_parent_subvol=0
    bi_nocow=0
    bi_depth=0
    bi_inodes_32bit=0
    bi_casefold=0, fixing
bcachefs (loop0): inode 1073741826:4294967295 has wrong backpointer:
  got       0:6676305307039241596
  should be 4096:6676305307039241596, fixing
bcachefs (loop0): inode 1073741824:4294967295 has wrong backpointer:
  got       0:6796365138662180125
  should be 4096:6796365138662180125, fixing
 done
bcachefs (loop0): check_xattrs...
bcachefs (loop0): hash table key at wrong offset: should be at 8440597020506023915
  u64s 7 type xattr 1073741824:945502502804528484:U32_MAX len 0 ver 0: user.xattr2:xattr2, fixing
==================================================================
BUG: KASAN: slab-use-after-free in bch2_str_hash_repair_key+0x2d42/0x3fa0 fs/bcachefs/str_hash.c:335
Read of size 8 at addr ffff88801239d128 by task syz.0.0/5329

CPU: 0 UID: 0 PID: 5329 Comm: syz.0.0 Not tainted 6.16.0-rc1-syzkaller-00203-g4774cfe3543a #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
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xd2/0x2b0 mm/kasan/report.c:521
 kasan_report+0x118/0x150 mm/kasan/report.c:634
 bch2_str_hash_repair_key+0x2d42/0x3fa0 fs/bcachefs/str_hash.c:335
 __bch2_str_hash_check_key+0xa65/0xd40 fs/bcachefs/str_hash.c:394
 bch2_str_hash_check_key fs/bcachefs/str_hash.h:429 [inline]
 check_xattr fs/bcachefs/fsck.c:2383 [inline]
 bch2_check_xattrs+0x933/0xcc0 fs/bcachefs/fsck.c:2396
 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:485 [inline]
 __bch2_run_recovery_passes+0x392/0x1010 fs/bcachefs/recovery_passes.c:540
 bch2_run_recovery_passes+0x184/0x210 fs/bcachefs/recovery_passes.c:611
 bch2_fs_recovery+0x25fd/0x3950 fs/bcachefs/recovery.c:989
 bch2_fs_start+0xa99/0xd90 fs/bcachefs/super.c:1203
 bch2_fs_get_tree+0xb02/0x14f0 fs/bcachefs/fs.c:2489
 vfs_get_tree+0x8f/0x2b0 fs/super.c:1802
 do_new_mount+0x24a/0xa40 fs/namespace.c:3885
 do_mount fs/namespace.c:4222 [inline]
 __do_sys_mount fs/namespace.c:4433 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4410
 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: 0033:0x7fb965d900ca
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:00007fb966c03e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fb966c03ef0 RCX: 00007fb965d900ca
RDX: 000020000000f640 RSI: 000020000000f680 RDI: 00007fb966c03eb0
RBP: 000020000000f640 R08: 00007fb966c03ef0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000020000000f680
R13: 00007fb966c03eb0 R14: 000000000000f631 R15: 0000200000000080
 </TASK>

Allocated by task 5329:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4328 [inline]
 __kmalloc_node_track_caller_noprof+0x271/0x4e0 mm/slub.c:4347
 __do_krealloc mm/slub.c:4905 [inline]
 krealloc_noprof+0x124/0x340 mm/slub.c:4958
 __bch2_trans_kmalloc+0x26c/0xc80 fs/bcachefs/btree_iter.c:3187
 bch2_trans_kmalloc_ip fs/bcachefs/btree_iter.h:604 [inline]
 bch2_trans_kmalloc fs/bcachefs/btree_iter.h:616 [inline]
 bch2_str_hash_repair_key+0x2a65/0x3fa0 fs/bcachefs/str_hash.c:251
 __bch2_str_hash_check_key+0xa65/0xd40 fs/bcachefs/str_hash.c:394
 bch2_str_hash_check_key fs/bcachefs/str_hash.h:429 [inline]
 check_xattr fs/bcachefs/fsck.c:2383 [inline]
 bch2_check_xattrs+0x933/0xcc0 fs/bcachefs/fsck.c:2396
 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:485 [inline]
 __bch2_run_recovery_passes+0x392/0x1010 fs/bcachefs/recovery_passes.c:540
 bch2_run_recovery_passes+0x184/0x210 fs/bcachefs/recovery_passes.c:611
 bch2_fs_recovery+0x25fd/0x3950 fs/bcachefs/recovery.c:989
 bch2_fs_start+0xa99/0xd90 fs/bcachefs/super.c:1203
 bch2_fs_get_tree+0xb02/0x14f0 fs/bcachefs/fs.c:2489
 vfs_get_tree+0x8f/0x2b0 fs/super.c:1802
 do_new_mount+0x24a/0xa40 fs/namespace.c:3885
 do_mount fs/namespace.c:4222 [inline]
 __do_sys_mount fs/namespace.c:4433 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4410
 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

Freed by task 5329:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2381 [inline]
 slab_free mm/slub.c:4643 [inline]
 kfree+0x18e/0x440 mm/slub.c:4842
 krealloc_noprof+0x1cd/0x340 mm/slub.c:-1
 __bch2_trans_kmalloc+0x26c/0xc80 fs/bcachefs/btree_iter.c:3187
 bch2_trans_kmalloc_ip fs/bcachefs/btree_iter.h:604 [inline]
 bch2_trans_kmalloc fs/bcachefs/btree_iter.h:616 [inline]
 bch2_hash_delete_at fs/bcachefs/str_hash.h:364 [inline]
 bch2_str_hash_repair_key+0x2fde/0x3fa0 fs/bcachefs/str_hash.c:289
 __bch2_str_hash_check_key+0xa65/0xd40 fs/bcachefs/str_hash.c:394
 bch2_str_hash_check_key fs/bcachefs/str_hash.h:429 [inline]
 check_xattr fs/bcachefs/fsck.c:2383 [inline]
 bch2_check_xattrs+0x933/0xcc0 fs/bcachefs/fsck.c:2396
 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:485 [inline]
 __bch2_run_recovery_passes+0x392/0x1010 fs/bcachefs/recovery_passes.c:540
 bch2_run_recovery_passes+0x184/0x210 fs/bcachefs/recovery_passes.c:611
 bch2_fs_recovery+0x25fd/0x3950 fs/bcachefs/recovery.c:989
 bch2_fs_start+0xa99/0xd90 fs/bcachefs/super.c:1203
 bch2_fs_get_tree+0xb02/0x14f0 fs/bcachefs/fs.c:2489
 vfs_get_tree+0x8f/0x2b0 fs/super.c:1802
 do_new_mount+0x24a/0xa40 fs/namespace.c:3885
 do_mount fs/namespace.c:4222 [inline]
 __do_sys_mount fs/namespace.c:4433 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4410
 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

The buggy address belongs to the object at ffff88801239d100
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 40 bytes inside of
 freed 128-byte region [ffff88801239d100, ffff88801239d180)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1239d
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801a441a00 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5329, tgid 5328 (syz.0.0), ts 76298329269, free_ts 73319450524
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704
 prep_new_page mm/page_alloc.c:1712 [inline]
 get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419
 alloc_slab_page mm/slub.c:2451 [inline]
 allocate_slab+0x8a/0x3b0 mm/slub.c:2619
 new_slab mm/slub.c:2673 [inline]
 ___slab_alloc+0xbfc/0x1480 mm/slub.c:3859
 __slab_alloc mm/slub.c:3949 [inline]
 __slab_alloc_node mm/slub.c:4024 [inline]
 slab_alloc_node mm/slub.c:4185 [inline]
 __do_kmalloc_node mm/slub.c:4327 [inline]
 __kmalloc_node_track_caller_noprof+0x2f8/0x4e0 mm/slub.c:4347
 __do_krealloc mm/slub.c:4905 [inline]
 krealloc_noprof+0x124/0x340 mm/slub.c:4958
 bch2_printbuf_make_room+0x1f5/0x360 fs/bcachefs/printbuf.c:59
 bch2_prt_printf+0x282/0x740 fs/bcachefs/printbuf.c:186
 bch2_bkey_val_to_text+0x34/0x150 fs/bcachefs/bkey_methods.c:327
 __bch2_str_hash_check_key+0x8f3/0xd40 fs/bcachefs/str_hash.c:390
 bch2_str_hash_check_key fs/bcachefs/str_hash.h:429 [inline]
 check_xattr fs/bcachefs/fsck.c:2383 [inline]
 bch2_check_xattrs+0x933/0xcc0 fs/bcachefs/fsck.c:2396
 bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:485 [inline]
 __bch2_run_recovery_passes+0x392/0x1010 fs/bcachefs/recovery_passes.c:540
 bch2_run_recovery_passes+0x184/0x210 fs/bcachefs/recovery_passes.c:611
 bch2_fs_recovery+0x25fd/0x3950 fs/bcachefs/recovery.c:989
page last free pid 5328 tgid 5328 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1248 [inline]
 __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706
 __slab_free+0x326/0x400 mm/slub.c:4554
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4148 [inline]
 slab_alloc_node mm/slub.c:4197 [inline]
 kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4204
 getname_flags+0xb8/0x540 fs/namei.c:146
 getname include/linux/fs.h:2903 [inline]
 __do_sys_symlinkat fs/namei.c:4772 [inline]
 __se_sys_symlinkat fs/namei.c:4769 [inline]
 __x64_sys_symlinkat+0x7a/0xb0 fs/namei.c:4769
 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

Memory state around the buggy address:
 ffff88801239d000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88801239d080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88801239d100: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff88801239d180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88801239d200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================