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 ffff88806d17f1b3 by task syz-executor.0/3919

CPU: 0 PID: 3919 Comm: syz-executor.0 Tainted: G        W          6.1.122-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:316 [inline]
 print_report+0x15f/0x4f0 mm/kasan/report.c:427
 kasan_report+0x136/0x160 mm/kasan/report.c:531
 strlen+0x54/0x60 lib/string.c:495
 set_de_name_and_namelen fs/reiserfs/namei.c:82 [inline]
 search_by_entry_key+0xa7b/0x1380 fs/reiserfs/namei.c:172
 reiserfs_find_entry+0xf47/0x19b0 fs/reiserfs/namei.c:322
 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: 0033:0x7f054ea7e05a
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:00007f054f7f6ee8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f054f7f6f80 RCX: 00007f054ea7e05a
RDX: 0000000020000140 RSI: 0000000020000340 RDI: 00007f054f7f6f40
RBP: 0000000020000140 R08: 00007f054f7f6f80 R09: 000000000120c083
R10: 000000000120c083 R11: 0000000000000246 R12: 0000000020000340
R13: 00007f054f7f6f40 R14: 0000000000001120 R15: 0000000020000380
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0001b45fc0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x6d17f
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001b48348 ffffea0001b46008 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 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 3922, tgid 3922 (sed), ts 87824197168, free_ts 87846911299
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2532
 prep_new_page mm/page_alloc.c:2539 [inline]
 get_page_from_freelist+0x3731/0x38d0 mm/page_alloc.c:4328
 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5605
 __folio_alloc+0xf/0x30 mm/page_alloc.c:5637
 vma_alloc_folio+0x486/0x990 mm/mempolicy.c:2243
 alloc_page_vma include/linux/gfp.h:284 [inline]
 do_cow_fault mm/memory.c:4648 [inline]
 do_fault mm/memory.c:4760 [inline]
 handle_pte_fault mm/memory.c:5029 [inline]
 __handle_mm_fault mm/memory.c:5171 [inline]
 handle_mm_fault+0x210c/0x5340 mm/memory.c:5292
 do_user_addr_fault arch/x86/mm/fault.c:1340 [inline]
 handle_page_fault arch/x86/mm/fault.c:1431 [inline]
 exc_page_fault+0x26f/0x620 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+0x12a6/0x15b0 mm/page_alloc.c:3384
 free_unref_page_list+0x663/0x900 mm/page_alloc.c:3525
 release_pages+0x24c4/0x27a0 mm/swap.c:1035
 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:254 [inline]
 tlb_flush_mmu+0xfc/0x210 mm/mmu_gather.c:261
 tlb_finish_mmu+0xce/0x1f0 mm/mmu_gather.c:361
 exit_mmap+0x3b3/0x980 mm/mmap.c:3250
 __mmput+0x115/0x3c0 kernel/fork.c:1200
 exit_mm+0x226/0x300 kernel/exit.c:565
 do_exit+0x9f1/0x26a0 kernel/exit.c:858
 do_group_exit+0x202/0x2b0 kernel/exit.c:1021
 __do_sys_exit_group kernel/exit.c:1032 [inline]
 __se_sys_exit_group kernel/exit.c:1030 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1030
 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

Memory state around the buggy address:
 ffff88806d17f080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88806d17f100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88806d17f180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                     ^
 ffff88806d17f200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88806d17f280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================