==================================================================
BUG: KASAN: use-after-free in bin_search_in_dir_item fs/reiserfs/namei.c:40 [inline]
BUG: KASAN: use-after-free in search_by_entry_key+0x80b/0x940 fs/reiserfs/namei.c:165
Read of size 4 at addr ffff8880426c73c4 by task syz-executor.4/27436

CPU: 0 PID: 27436 Comm: syz-executor.4 Not tainted 6.7.0-rc7-syzkaller-00041-gf016f7547aee #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xc4/0x620 mm/kasan/report.c:475
 kasan_report+0xda/0x110 mm/kasan/report.c:588
 bin_search_in_dir_item fs/reiserfs/namei.c:40 [inline]
 search_by_entry_key+0x80b/0x940 fs/reiserfs/namei.c:165
 reiserfs_find_entry+0x1dc/0xe70 fs/reiserfs/namei.c:322
 reiserfs_lookup+0x1f5/0x690 fs/reiserfs/namei.c:368
 __lookup_slow+0x24d/0x450 fs/namei.c:1694
 lookup_one_len+0x17d/0x1b0 fs/namei.c:2746
 reiserfs_lookup_privroot+0x94/0x200 fs/reiserfs/xattr.c:977
 reiserfs_fill_super+0x1ab6/0x3160 fs/reiserfs/super.c:2192
 mount_bdev+0x1f3/0x2e0 fs/super.c:1650
 legacy_get_tree+0x109/0x220 fs/fs_context.c:662
 vfs_get_tree+0x8c/0x370 fs/super.c:1771
 do_new_mount fs/namespace.c:3337 [inline]
 path_mount+0x1492/0x1ed0 fs/namespace.c:3664
 do_mount fs/namespace.c:3677 [inline]
 __do_sys_mount fs/namespace.c:3886 [inline]
 __se_sys_mount fs/namespace.c:3863 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:3863
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7fa553c7e3ea
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:00007fa554a8fee8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fa554a8ff80 RCX: 00007fa553c7e3ea
RDX: 0000000020000080 RSI: 0000000020000140 RDI: 00007fa554a8ff40
RBP: 0000000020000080 R08: 00007fa554a8ff80 R09: 000000000120c083
R10: 000000000120c083 R11: 0000000000000206 R12: 0000000020000140
R13: 00007fa554a8ff40 R14: 000000000000111b R15: 0000000020000180
 </TASK>

The buggy address belongs to the physical page:
page:ffffea000109b1c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x426c7
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 ffffea0001022f08 ffffea00010e85c8 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 27440, tgid 27440 (modprobe), ts 1201206641097, free_ts 1201338699979
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2d0/0x350 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1544 [inline]
 get_page_from_freelist+0xa25/0x36d0 mm/page_alloc.c:3312
 __alloc_pages+0x22e/0x2420 mm/page_alloc.c:4568
 alloc_pages_mpol+0x258/0x5f0 mm/mempolicy.c:2133
 vma_alloc_folio+0xad/0x220 mm/mempolicy.c:2172
 alloc_page_vma include/linux/gfp.h:292 [inline]
 do_cow_fault mm/memory.c:4652 [inline]
 do_fault mm/memory.c:4765 [inline]
 do_pte_missing mm/memory.c:3731 [inline]
 handle_pte_fault mm/memory.c:5039 [inline]
 __handle_mm_fault+0x100c/0x3d70 mm/memory.c:5180
 handle_mm_fault+0x47a/0xa10 mm/memory.c:5345
 do_user_addr_fault+0x3d1/0x1000 arch/x86/mm/fault.c:1413
 handle_page_fault arch/x86/mm/fault.c:1505 [inline]
 exc_page_fault+0x5d/0xc0 arch/x86/mm/fault.c:1561
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1137 [inline]
 free_unref_page_prepare+0x4fa/0xaa0 mm/page_alloc.c:2347
 free_unref_page_list+0xe6/0xb40 mm/page_alloc.c:2533
 release_pages+0x32a/0x14f0 mm/swap.c:1042
 tlb_batch_pages_flush+0x9a/0x190 mm/mmu_gather.c:98
 tlb_flush_mmu_free mm/mmu_gather.c:293 [inline]
 tlb_flush_mmu mm/mmu_gather.c:300 [inline]
 tlb_finish_mmu+0x14b/0x6f0 mm/mmu_gather.c:392
 exit_mmap+0x38b/0xa70 mm/mmap.c:3321
 __mmput+0x12a/0x4d0 kernel/fork.c:1349
 mmput+0x62/0x70 kernel/fork.c:1371
 exit_mm kernel/exit.c:567 [inline]
 do_exit+0x9a5/0x2ad0 kernel/exit.c:856
 do_group_exit+0xd4/0x2a0 kernel/exit.c:1018
 __do_sys_exit_group kernel/exit.c:1029 [inline]
 __se_sys_exit_group kernel/exit.c:1027 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1027
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

Memory state around the buggy address:
 ffff8880426c7280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880426c7300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880426c7380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff8880426c7400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880426c7480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================