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 bin_search_in_dir_item fs/reiserfs/namei.c:40 [inline]
BUG: KASAN: use-after-free in search_by_entry_key+0x579/0x1380 fs/reiserfs/namei.c:165
Read of size 4 at addr ffff8880720c0004 by task syz-executor.0/5456

CPU: 0 PID: 5456 Comm: syz-executor.0 Not tainted 6.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0x163/0x540 mm/kasan/report.c:475
 kasan_report+0x142/0x170 mm/kasan/report.c:588
 bin_search_in_dir_item fs/reiserfs/namei.c:40 [inline]
 search_by_entry_key+0x579/0x1380 fs/reiserfs/namei.c:165
 reiserfs_find_entry+0xf4b/0x19b0 fs/reiserfs/namei.c:322
 reiserfs_lookup+0x1e2/0x580 fs/reiserfs/namei.c:368
 __lookup_slow+0x282/0x3e0 fs/namei.c:1694
 lookup_one_len+0x18b/0x2d0 fs/namei.c:2746
 reiserfs_lookup_privroot+0x89/0x180 fs/reiserfs/xattr.c:977
 reiserfs_fill_super+0x195b/0x2620 fs/reiserfs/super.c:2192
 mount_bdev+0x237/0x300 fs/super.c:1650
 legacy_get_tree+0xef/0x190 fs/fs_context.c:662
 vfs_get_tree+0x8c/0x280 fs/super.c:1771
 do_new_mount+0x28f/0xae0 fs/namespace.c:3337
 do_mount fs/namespace.c:3677 [inline]
 __do_sys_mount fs/namespace.c:3886 [inline]
 __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3863
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0xe0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f991c47e05a
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:00007f991d24eee8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f991d24ef80 RCX: 00007f991c47e05a
RDX: 0000000020000140 RSI: 0000000020000340 RDI: 00007f991d24ef40
RBP: 0000000020000140 R08: 00007f991d24ef80 R09: 000000000120c083
R10: 000000000120c083 R11: 0000000000000246 R12: 0000000020000340
R13: 00007f991d24ef40 R14: 0000000000001120 R15: 0000000020000380
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0001c83000 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x720c0
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 ffffea0001c83048 ffff8880b98422b0 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 14858410955, free_ts 16399995779
 split_map_pages+0x24a/0x510 mm/compaction.c:97
 isolate_freepages_range+0x476/0x4d0 mm/compaction.c:774
 alloc_contig_range+0x62e/0x9a0 mm/page_alloc.c:6411
 __alloc_contig_pages mm/page_alloc.c:6434 [inline]
 alloc_contig_pages+0x3f4/0x4f0 mm/page_alloc.c:6514
 debug_vm_pgtable_alloc_huge_page+0xb9/0x110 mm/debug_vm_pgtable.c:1095
 init_args+0x837/0xb10 mm/debug_vm_pgtable.c:1277
 debug_vm_pgtable+0xe0/0x540 mm/debug_vm_pgtable.c:1315
 do_one_initcall+0x234/0x800 init/main.c:1236
 do_initcall_level+0x157/0x210 init/main.c:1298
 do_initcalls+0x3f/0x80 init/main.c:1314
 kernel_init_freeable+0x429/0x5c0 init/main.c:1551
 kernel_init+0x1d/0x2a0 init/main.c:1441
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
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+0x925/0xa40 mm/page_alloc.c:2347
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2487
 free_contig_range+0x9e/0x150 mm/page_alloc.c:6536
 destroy_args+0x8a/0x880 mm/debug_vm_pgtable.c:1028
 debug_vm_pgtable+0x4ba/0x540 mm/debug_vm_pgtable.c:1408
 do_one_initcall+0x234/0x800 init/main.c:1236
 do_initcall_level+0x157/0x210 init/main.c:1298
 do_initcalls+0x3f/0x80 init/main.c:1314
 kernel_init_freeable+0x429/0x5c0 init/main.c:1551
 kernel_init+0x1d/0x2a0 init/main.c:1441
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

Memory state around the buggy address:
 ffff8880720bff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880720bff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880720c0000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff8880720c0080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880720c0100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================