==================================================================
BUG: KASAN: out-of-bounds in strlen+0x53/0x60 lib/string.c:502
Read of size 1 at addr ffff8880693ee008 by task syz.3.20/4437

CPU: 1 PID: 4437 Comm: syz.3.20 Not tainted 6.1.140-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0xa8/0x220 mm/kasan/report.c:427
 kasan_report+0x10b/0x140 mm/kasan/report.c:531
 strlen+0x53/0x60 lib/string.c:502
 _Z16__fortify_strlenPKcU17pass_object_size1 include/linux/fortify-string.h:196 [inline]
 set_de_name_and_namelen fs/reiserfs/namei.c:82 [inline]
 search_by_entry_key+0xa84/0x1370 fs/reiserfs/namei.c:172
 reiserfs_readdir_inode+0x22c/0x1230 fs/reiserfs/dir.c:98
 iterate_dir+0x218/0x560 fs/readdir.c:-1
 __do_sys_getdents fs/readdir.c:286 [inline]
 __se_sys_getdents+0xe5/0x250 fs/readdir.c:271
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fdc22f8e969
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:00007fdc23d39038 EFLAGS: 00000246 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 00007fdc231b5fa0 RCX: 00007fdc22f8e969
RDX: 0000000000009005 RSI: 0000200000000280 RDI: 0000000000000005
RBP: 00007fdc23010ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fdc231b5fa0 R15: 00007fff3338cd18
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0001a4fb80 refcount:1 mapcount:1 mapping:0000000000000000 index:0x7f0072009 pfn:0x693ee
memcg:ffff88807a5f6000
anon flags: 0xfff800000a0014(uptodate|lru|mappedtodisk|swapbacked|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff800000a0014 ffffea0001a0b048 ffffea0001a4fbc8 ffff88807e087ee1
raw: 00000007f0072009 0000000000000000 0000000100000000 ffff88807a5f6000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Movable, gfp_mask 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO), pid 4475, tgid 4474 (syz.2.31), ts 93004650757, free_ts 91585512780
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532
 prep_new_page mm/page_alloc.c:2539 [inline]
 get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328
 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5606
 __folio_alloc+0xe/0x30 mm/page_alloc.c:5638
 vma_alloc_folio+0x4a3/0x900 mm/mempolicy.c:2243
 alloc_page_vma include/linux/gfp.h:284 [inline]
 do_anonymous_page mm/memory.c:4191 [inline]
 handle_pte_fault mm/memory.c:5029 [inline]
 __handle_mm_fault mm/memory.c:5173 [inline]
 handle_mm_fault+0x2242/0x3e70 mm/memory.c:5294
 do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340
 handle_page_fault arch/x86/mm/fault.c:1431 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1459 [inline]
 free_pcp_prepare mm/page_alloc.c:1509 [inline]
 free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384
 free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3525
 release_pages+0x1f92/0x2200 mm/swap.c:1035
 __pagevec_release+0x6d/0xe0 mm/swap.c:1055
 pagevec_release include/linux/pagevec.h:71 [inline]
 folio_batch_release include/linux/pagevec.h:135 [inline]
 shmem_undo_range+0x75b/0x2050 mm/shmem.c:946
 shmem_truncate_range mm/shmem.c:1062 [inline]
 shmem_evict_inode+0x248/0xa40 mm/shmem.c:1171
 evict+0x485/0x870 fs/inode.c:705
 __dentry_kill+0x431/0x650 fs/dcache.c:611
 dentry_kill+0xb8/0x290 fs/dcache.c:-1
 dput+0xfa/0x1d0 fs/dcache.c:918
 __fput+0x5e0/0x920 fs/file_table.c:328
 task_work_run+0x1ca/0x250 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87

Memory state around the buggy address:
 ffff8880693edf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880693edf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880693ee000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                         ^
 ffff8880693ee080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880693ee100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================