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 tea hash to sort names
==================================================================
BUG: KASAN: out-of-bounds in leaf_paste_entries+0x794/0x1130 fs/reiserfs/lbalance.c:1377
Read of size 18446744073709551584 at addr ffff88805f9b7fa4 by task syz.0.16/5126

CPU: 1 PID: 5126 Comm: syz.0.16 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x235/0x290 mm/kasan/generic.c:189
 memmove+0x25/0x60 mm/kasan/shadow.c:54
 leaf_paste_entries+0x794/0x1130 fs/reiserfs/lbalance.c:1377
 balance_leaf_finish_node_paste_dirent fs/reiserfs/do_balan.c:1295 [inline]
 balance_leaf_finish_node_paste fs/reiserfs/do_balan.c:1321 [inline]
 balance_leaf_finish_node fs/reiserfs/do_balan.c:1364 [inline]
 balance_leaf+0xb2e5/0x10ec0 fs/reiserfs/do_balan.c:1452
 do_balance+0x318/0x930 fs/reiserfs/do_balan.c:1888
 reiserfs_paste_into_item+0x6dd/0x810 fs/reiserfs/stree.c:2159
 reiserfs_add_entry+0xa42/0xe10 fs/reiserfs/namei.c:567
 reiserfs_mkdir+0x6bc/0x920 fs/reiserfs/namei.c:862
 xattr_mkdir fs/reiserfs/xattr.c:76 [inline]
 create_privroot fs/reiserfs/xattr.c:889 [inline]
 reiserfs_xattr_init+0x331/0x720 fs/reiserfs/xattr.c:1012
 reiserfs_fill_super+0x1fe6/0x2440 fs/reiserfs/super.c:2179
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fc5442fd30a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc54355fe58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fc54355fee0 RCX: 00007fc5442fd30a
RDX: 0000200000000080 RSI: 0000200000000040 RDI: 00007fc54355fea0
RBP: 0000200000000080 R08: 00007fc54355fee0 R09: 000000000000800c
R10: 000000000000800c R11: 0000000000000246 R12: 0000200000000040
R13: 00007fc54355fea0 R14: 0000000000001118 R15: 0000200000001380
 </TASK>

The buggy address belongs to the page:
page:ffffea00017e6dc0 refcount:3 mapcount:0 mapping:ffff88814081daf0 index:0x213 pfn:0x5f9b7
memcg:ffff8880763a4000
aops:def_blk_aops ino:700000
flags: 0xfff00000002022(referenced|active|private|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002022 0000000000000000 dead000000000122 ffff88814081daf0
raw: 0000000000000213 ffff888024973ae0 00000003ffffffff ffff8880763a4000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Movable, gfp_mask 0x108c48(GFP_NOFS|__GFP_NOFAIL|__GFP_HARDWALL|__GFP_MOVABLE), pid 5126, ts 104028396626, free_ts 92706799644
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5487
 __page_cache_alloc+0xce/0x440 mm/filemap.c:1022
 pagecache_get_page+0x9b6/0xf10 mm/filemap.c:1940
 find_or_create_page include/linux/pagemap.h:420 [inline]
 grow_dev_page fs/buffer.c:949 [inline]
 grow_buffers fs/buffer.c:1014 [inline]
 __getblk_slow fs/buffer.c:1041 [inline]
 __getblk_gfp+0x247/0xb60 fs/buffer.c:1336
 sb_getblk include/linux/buffer_head.h:361 [inline]
 search_by_key+0x46c/0x4470 fs/reiserfs/stree.c:672
 reiserfs_read_locked_inode+0x195/0x26b0 fs/reiserfs/inode.c:1557
 reiserfs_fill_super+0x12af/0x2440 fs/reiserfs/super.c:2075
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
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+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page_list+0x119/0x820 mm/page_alloc.c:3433
 release_pages+0x186c/0x1be0 mm/swap.c:963
 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:240 [inline]
 tlb_flush_mmu mm/mmu_gather.c:247 [inline]
 tlb_finish_mmu+0x176/0x300 mm/mmu_gather.c:338
 unmap_region+0x344/0x3b0 mm/mmap.c:2669
 __do_munmap+0x9f8/0xdf0 mm/mmap.c:2899
 __vm_munmap+0x140/0x240 mm/mmap.c:2952
 __do_sys_munmap mm/mmap.c:2978 [inline]
 __se_sys_munmap mm/mmap.c:2974 [inline]
 __x64_sys_munmap+0x67/0x70 mm/mmap.c:2974
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff88805f9b7e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805f9b7f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805f9b7f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                               ^
 ffff88805f9b8000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805f9b8080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================