loop0: detected capacity change from 0 to 512
EXT4-fs: Ignoring removed oldalloc option
EXT4-fs error (device loop0): ext4_xattr_ibody_find:2240: inode #15: comm syz.0.0: corrupted in-inode xattr: invalid ea_ino
EXT4-fs error (device loop0): ext4_orphan_get:1394: comm syz.0.0: couldn't read orphan inode 15 (err -117)
EXT4-fs (loop0): mounted filesystem 00000007-0000-0000-0000-000000000000 r/w without journal. Quota mode: none.
==================================================================
BUG: KASAN: use-after-free in ext4_insert_dentry+0x3cd/0x780 fs/ext4/namei.c:2119
Write of size 251 at addr ffff888043500f14 by task syz.0.0/5325

CPU: 0 UID: 0 PID: 5325 Comm: syz.0.0 Not tainted 6.14.0-rc5-syzkaller-00268-g1110ce6a1e34 #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:408 [inline]
 print_report+0x16e/0x5b0 mm/kasan/report.c:521
 kasan_report+0x143/0x180 mm/kasan/report.c:634
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 __asan_memcpy+0x40/0x70 mm/kasan/shadow.c:106
 ext4_insert_dentry+0x3cd/0x780 fs/ext4/namei.c:2119
 add_dirent_to_buf+0x315/0x660 fs/ext4/namei.c:2164
 make_indexed_dir+0xcaf/0x1280 fs/ext4/namei.c:2361
 ext4_add_entry+0xb36/0xd30 fs/ext4/namei.c:2462
 ext4_add_nondir+0x8d/0x290 fs/ext4/namei.c:2803
 ext4_symlink+0xa10/0xda0 fs/ext4/namei.c:3440
 vfs_symlink+0x137/0x2e0 fs/namei.c:4671
 do_symlinkat+0x222/0x3a0 fs/namei.c:4697
 __do_sys_symlink fs/namei.c:4718 [inline]
 __se_sys_symlink fs/namei.c:4716 [inline]
 __x64_sys_symlink+0x7a/0x90 fs/namei.c:4716
 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: 0033:0x7f8a7498d169
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007f8a7581f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 00007f8a74ba5fa0 RCX: 00007f8a7498d169
RDX: 0000000000000000 RSI: 0000400000000cc0 RDI: 0000400000000dc0
RBP: 00007f8a74a0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f8a74ba5fa0 R15: 00007ffcbdf8b538
 </TASK>

The buggy address belongs to the physical page:
page: refcount:3 mapcount:0 mapping:ffff8880004acd78 index:0x3f pfn:0x43500
memcg:ffff888012850000
aops:def_blk_aops ino:700000 dentry name(?):""
flags: 0x4fff10000004014(referenced|dirty|private|node=1|zone=1|lastcpupid=0x7ff)
raw: 04fff10000004014 0000000000000000 dead000000000122 ffff8880004acd78
raw: 000000000000003f ffff88801ac990e8 00000003ffffffff ffff888012850000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x148c40(GFP_NOFS|__GFP_NOFAIL|__GFP_COMP|__GFP_HARDWALL), pid 5325, tgid 5324 (syz.0.0), ts 69529603698, free_ts 69400950888
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4740
 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270
 alloc_frozen_pages_noprof mm/mempolicy.c:2341 [inline]
 alloc_pages_noprof+0x121/0x190 mm/mempolicy.c:2361
 folio_alloc_noprof+0x1e/0x30 mm/mempolicy.c:2371
 filemap_alloc_folio_noprof+0xe1/0x540 mm/filemap.c:1019
 __filemap_get_folio+0x438/0xae0 mm/filemap.c:1970
 grow_dev_folio fs/buffer.c:1039 [inline]
 grow_buffers fs/buffer.c:1105 [inline]
 __getblk_slow fs/buffer.c:1131 [inline]
 bdev_getblk+0x1d4/0x670 fs/buffer.c:1431
 getblk_unmovable include/linux/buffer_head.h:369 [inline]
 ext4_getblk+0x31b/0x880 fs/ext4/inode.c:864
 ext4_bread+0x2e/0x180 fs/ext4/inode.c:912
 ext4_append+0x327/0x5c0 fs/ext4/namei.c:83
 make_indexed_dir+0x3ff/0x1280 fs/ext4/namei.c:2282
 ext4_add_entry+0xb36/0xd30 fs/ext4/namei.c:2462
 ext4_add_nondir+0x8d/0x290 fs/ext4/namei.c:2803
 ext4_symlink+0xa10/0xda0 fs/ext4/namei.c:3440
page last free pid 4670 tgid 4670 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660
 discard_slab mm/slub.c:2684 [inline]
 __put_partials+0x160/0x1c0 mm/slub.c:3153
 put_cpu_partial+0x17c/0x250 mm/slub.c:3228
 __slab_free+0x290/0x380 mm/slub.c:4479
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4115 [inline]
 slab_alloc_node mm/slub.c:4164 [inline]
 kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4171
 skb_clone+0x20c/0x390 net/core/skbuff.c:1994
 hci_send_cmd_sync net/bluetooth/hci_core.c:4048 [inline]
 hci_cmd_work+0xe7/0x6c0 net/bluetooth/hci_core.c:4084
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd30 kernel/workqueue.c:3400
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff888043500f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888043500f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888043501000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888043501080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888043501100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================