REISERFS (device loop0): using ordered data mode
reiserfs: using flush barriers
REISERFS (device loop0): journal params: device loop0, size 512, journal first block 18, max trans len 256, max batch 225, max commit age 30, max trans age 30
REISERFS (device loop0): checking transaction log (loop0)
REISERFS (device loop0): Using r5 hash to sort names
==================================================================
BUG: KASAN: use-after-free in strlen+0x54/0x60 lib/string.c:566
Read of size 1 at addr ffff88806fea97a3 by task syz-executor160/3499

CPU: 1 PID: 3499 Comm: syz-executor160 Not tainted 5.15.118-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_address_description+0x63/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
 strlen+0x54/0x60 lib/string.c:566
 set_de_name_and_namelen fs/reiserfs/namei.c:82 [inline]
 linear_search_in_dir_item fs/reiserfs/namei.c:262 [inline]
 reiserfs_find_entry+0x97e/0x19b0 fs/reiserfs/namei.c:331
 reiserfs_lookup+0x1e6/0x4b0 fs/reiserfs/namei.c:368
 __lookup_slow+0x275/0x3d0 fs/namei.c:1659
 lookup_one_len+0x187/0x2d0 fs/namei.c:2688
 reiserfs_lookup_privroot+0x85/0x1e0 fs/reiserfs/xattr.c:980
 reiserfs_fill_super+0x191e/0x2690 fs/reiserfs/super.c:2196
 mount_bdev+0x2c9/0x3f0 fs/super.c:1378
 legacy_get_tree+0xeb/0x180 fs/fs_context.c:610
 vfs_get_tree+0x88/0x270 fs/super.c:1508
 do_new_mount+0x28b/0xae0 fs/namespace.c:2994
 do_mount fs/namespace.c:3337 [inline]
 __do_sys_mount fs/namespace.c:3545 [inline]
 __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3522
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fe090ef3afa
Code: 83 c4 08 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff9246a128 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fe090ef3afa
RDX: 00000000200000c0 RSI: 0000000020000040 RDI: 00007fff9246a130
RBP: 00007fff9246a130 R08: 00007fff9246a170 R09: 000000000000111c
R10: 0000000000008001 R11: 0000000000000286 R12: 0000000000000004
R13: 00005555558a02c0 R14: 00007fff9246a170 R15: 0000000000000000
 </TASK>

The buggy address belongs to the page:
page:ffffea0001bfaa40 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x6fea9
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001bfaa88 ffff8880b9b3fd20 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Movable, gfp_mask 0x8(__GFP_MOVABLE), pid 1, ts 9801117631, free_ts 10919455783
 split_map_pages+0x246/0x510 mm/compaction.c:99
 isolate_freepages_range+0x47c/0x4e0 mm/compaction.c:749
 alloc_contig_range+0xc2b/0xf90 mm/page_alloc.c:9214
 __alloc_contig_pages mm/page_alloc.c:9238 [inline]
 alloc_contig_pages+0x3ea/0x4e0 mm/page_alloc.c:9318
 debug_vm_pgtable_alloc_huge_page+0xb9/0x108 mm/debug_vm_pgtable.c:1085
 init_args+0xa3e/0xdb5 mm/debug_vm_pgtable.c:1207
 debug_vm_pgtable+0xaa/0x462 mm/debug_vm_pgtable.c:1245
 do_one_initcall+0x22b/0x7a0 init/main.c:1306
 do_initcall_level+0x157/0x207 init/main.c:1379
 do_initcalls+0x49/0x86 init/main.c:1395
 kernel_init_freeable+0x43c/0x5c5 init/main.c:1619
 kernel_init+0x19/0x290 init/main.c:1510
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396
 free_contig_range+0x95/0xf0 mm/page_alloc.c:9340
 destroy_args+0xfe/0x97f mm/debug_vm_pgtable.c:1018
 debug_vm_pgtable+0x40d/0x462 mm/debug_vm_pgtable.c:1331
 do_one_initcall+0x22b/0x7a0 init/main.c:1306
 do_initcall_level+0x157/0x207 init/main.c:1379
 do_initcalls+0x49/0x86 init/main.c:1395
 kernel_init_freeable+0x43c/0x5c5 init/main.c:1619
 kernel_init+0x19/0x290 init/main.c:1510
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

Memory state around the buggy address:
 ffff88806fea9680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88806fea9700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88806fea9780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff88806fea9800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88806fea9880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================