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:495
Read of size 1 at addr ffff8880667957a3 by task syz-executor.0/3927

CPU: 0 PID: 3927 Comm: syz-executor.0 Not tainted 6.1.119-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:284 [inline]
 print_report+0x15f/0x4f0 mm/kasan/report.c:395
 kasan_report+0x136/0x160 mm/kasan/report.c:495
 strlen+0x54/0x60 lib/string.c:495
 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+0x27e/0x3d0 fs/namei.c:1690
 lookup_one_len+0x187/0x2d0 fs/namei.c:2740
 reiserfs_lookup_privroot+0x85/0x1e0 fs/reiserfs/xattr.c:973
 reiserfs_fill_super+0x1957/0x2620 fs/reiserfs/super.c:2192
 mount_bdev+0x2c9/0x3f0 fs/super.c:1443
 legacy_get_tree+0xeb/0x180 fs/fs_context.c:632
 vfs_get_tree+0x88/0x270 fs/super.c:1573
 do_new_mount+0x2ba/0xb40 fs/namespace.c:3056
 do_mount fs/namespace.c:3399 [inline]
 __do_sys_mount fs/namespace.c:3607 [inline]
 __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3584
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2cab27e22a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 09 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2cabf1fee8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f2cabf1ff80 RCX: 00007f2cab27e22a
RDX: 00000000200000c0 RSI: 0000000020000040 RDI: 00007f2cabf1ff40
RBP: 00000000200000c0 R08: 00007f2cabf1ff80 R09: 0000000000008001
R10: 0000000000008001 R11: 0000000000000246 R12: 0000000020000040
R13: 00007f2cabf1ff40 R14: 0000000000001122 R15: 0000000020000080
 </TASK>

The buggy address belongs to the physical page:
page:ffffea000199e540 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x66795
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffff8880b98411e0 ffff8880b98411e0 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, tgid 1 (swapper/0), ts 16162700074, free_ts 17425179304
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2517
 split_map_pages+0x246/0x510 mm/compaction.c:97
 isolate_freepages_range+0x47c/0x4e0 mm/compaction.c:735
 alloc_contig_range+0x62a/0x990 mm/page_alloc.c:9425
 __alloc_contig_pages mm/page_alloc.c:9448 [inline]
 alloc_contig_pages+0x3f0/0x4e0 mm/page_alloc.c:9528
 debug_vm_pgtable_alloc_huge_page+0xb9/0x108 mm/debug_vm_pgtable.c:1098
 init_args+0xc92/0x1022 mm/debug_vm_pgtable.c:1221
 debug_vm_pgtable+0xaa/0x46b mm/debug_vm_pgtable.c:1259
 do_one_initcall+0x265/0x8f0 init/main.c:1298
 do_initcall_level+0x157/0x207 init/main.c:1371
 do_initcalls+0x49/0x86 init/main.c:1387
 kernel_init_freeable+0x45c/0x60f init/main.c:1626
 kernel_init+0x19/0x290 init/main.c:1514
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1444 [inline]
 free_pcp_prepare mm/page_alloc.c:1494 [inline]
 free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3369
 free_unref_page+0x33/0x3e0 mm/page_alloc.c:3464
 free_contig_range+0x9a/0x150 mm/page_alloc.c:9550
 destroy_args+0xfe/0x997 mm/debug_vm_pgtable.c:1031
 debug_vm_pgtable+0x416/0x46b mm/debug_vm_pgtable.c:1354
 do_one_initcall+0x265/0x8f0 init/main.c:1298
 do_initcall_level+0x157/0x207 init/main.c:1371
 do_initcalls+0x49/0x86 init/main.c:1387
 kernel_init_freeable+0x45c/0x60f init/main.c:1626
 kernel_init+0x19/0x290 init/main.c:1514
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Memory state around the buggy address:
 ffff888066795680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888066795700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888066795780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff888066795800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888066795880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================