==================================================================
BUG: KASAN: slab-use-after-free in configfs_dirent_is_ready+0x6b/0x70 fs/configfs/dir.c:363
Read of size 4 at addr ffff88801f30ca38 by task syz.4.325/6974

CPU: 0 UID: 0 PID: 6974 Comm: syz.4.325 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
 configfs_dirent_is_ready+0x6b/0x70 fs/configfs/dir.c:363
 create_link fs/configfs/symlink.c:85 [inline]
 configfs_symlink+0x5c4/0x11f0 fs/configfs/symlink.c:199
 vfs_symlink fs/namei.c:5794 [inline]
 vfs_symlink+0x178/0x4d0 fs/namei.c:5773
 filename_symlinkat+0x2a6/0x560 fs/namei.c:5819
 __do_sys_symlinkat fs/namei.c:5839 [inline]
 __se_sys_symlinkat fs/namei.c:5834 [inline]
 __x64_sys_symlinkat+0x9c/0xe0 fs/namei.c:5834
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4b8079e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4b81703028 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007f4b80a26090 RCX: 00007f4b8079e159
RDX: 0000200000000200 RSI: ffffffffffffff9c RDI: 00002000000001c0
RBP: 00007f4b80835024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4b80a26128 R14: 00007f4b80a26090 R15: 00007ffe56a433e8
 </TASK>

Allocated by task 6973:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4683 [inline]
 slab_alloc_node mm/slub.c:4996 [inline]
 kmem_cache_alloc_noprof+0x269/0x6a0 mm/slub.c:5010
 configfs_new_dirent+0x52/0x570 fs/configfs/dir.c:193
 configfs_make_dirent+0x36/0x1a0 fs/configfs/dir.c:259
 configfs_create_dir+0xbd/0x5c0 fs/configfs/dir.c:304
 configfs_attach_item fs/configfs/dir.c:863 [inline]
 configfs_attach_group+0x2a/0x440 fs/configfs/dir.c:898
 configfs_mkdir+0x657/0xd40 fs/configfs/dir.c:1423
 vfs_mkdir+0x364/0x850 fs/namei.c:5410
 filename_mkdirat+0x48b/0x5e0 fs/namei.c:5443
 __do_sys_mkdirat fs/namei.c:5464 [inline]
 __se_sys_mkdirat fs/namei.c:5461 [inline]
 __x64_sys_mkdirat+0x89/0xc0 fs/namei.c:5461
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6973:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2748 [inline]
 slab_free mm/slub.c:6499 [inline]
 kmem_cache_free+0x127/0x6c0 mm/slub.c:6626
 release_configfs_dirent fs/configfs/configfs_internal.h:139 [inline]
 release_configfs_dirent fs/configfs/configfs_internal.h:134 [inline]
 configfs_put fs/configfs/configfs_internal.h:156 [inline]
 configfs_d_iput+0x20d/0x290 fs/configfs/dir.c:63
 dentry_unlink_inode+0x265/0x470 fs/dcache.c:477
 d_delete fs/dcache.c:2700 [inline]
 d_delete+0x213/0x280 fs/dcache.c:2687
 d_delete_notify include/linux/fsnotify.h:379 [inline]
 vfs_rmdir fs/namei.c:5528 [inline]
 vfs_rmdir+0x4ab/0x8a0 fs/namei.c:5488
 filename_rmdir+0x31a/0x5c0 fs/namei.c:5572
 __do_sys_rmdir fs/namei.c:5595 [inline]
 __se_sys_rmdir fs/namei.c:5592 [inline]
 __x64_sys_rmdir+0x46/0x70 fs/namei.c:5592
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88801f30ca00
 which belongs to the cache configfs_dir_cache of size 96
The buggy address is located 56 bytes inside of
 freed 96-byte region [ffff88801f30ca00, ffff88801f30ca60)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1f30c
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff888020e9c140 dead000000000122 0000000000000000
raw: 0000000000000000 0000000200200020 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 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 3184379675
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x110d/0x35d0 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x2eb/0x3300 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3347 [inline]
 allocate_slab mm/slub.c:3462 [inline]
 new_slab+0xa9/0x6e0 mm/slub.c:3513
 refill_objects+0xe3/0x410 mm/slub.c:7410
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 kmem_cache_alloc_noprof+0x4c4/0x6a0 mm/slub.c:5010
 configfs_new_dirent+0x52/0x570 fs/configfs/dir.c:193
 configfs_make_dirent+0x36/0x1a0 fs/configfs/dir.c:259
 configfs_create_dir+0xbd/0x5c0 fs/configfs/dir.c:304
 configfs_attach_item fs/configfs/dir.c:863 [inline]
 configfs_attach_group+0x2a/0x440 fs/configfs/dir.c:898
 configfs_register_subsystem+0x2c7/0x5e0 fs/configfs/dir.c:1908
 init_dlm+0x4e/0x120 fs/dlm/main.c:41
 do_one_initcall+0x11c/0x6f0 init/main.c:1357
 do_initcall_level init/main.c:1419 [inline]
 do_initcalls init/main.c:1435 [inline]
 do_basic_setup init/main.c:1455 [inline]
 kernel_init_freeable+0x6ea/0x7b0 init/main.c:1670
 kernel_init+0x21/0x1e0 init/main.c:1560
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88801f30c900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88801f30c980: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff88801f30ca00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                                        ^
 ffff88801f30ca80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
 ffff88801f30cb00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
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