==================================================================
BUG: KASAN: use-after-free in leaf_paste_in_buffer+0x631/0xab0
Read of size 48 at addr ffff88805e667ff0 by task syz-executor.1/10970

CPU: 0 PID: 10970 Comm: syz-executor.1 Not tainted 5.15.124-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_address_description+0x63/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
 kasan_check_range+0x27e/0x290 mm/kasan/generic.c:189
 memcpy+0x25/0x60 mm/kasan/shadow.c:65
 leaf_paste_in_buffer+0x631/0xab0
 leaf_copy_dir_entries+0x71a/0xc60 fs/reiserfs/lbalance.c:108
 leaf_copy_boundary_item+0xbbe/0x21b0 fs/reiserfs/lbalance.c:168
 leaf_copy_items fs/reiserfs/lbalance.c:551 [inline]
 leaf_move_items+0xcd0/0x28a0 fs/reiserfs/lbalance.c:726
 leaf_shift_left+0xba/0x430 fs/reiserfs/lbalance.c:750
 balance_leaf_when_delete_left fs/reiserfs/do_balan.c:194 [inline]
 balance_leaf_when_delete fs/reiserfs/do_balan.c:272 [inline]
 balance_leaf+0x228e/0x12510 fs/reiserfs/do_balan.c:1393
 do_balance+0x309/0x8f0 fs/reiserfs/do_balan.c:1888
 reiserfs_delete_solid_item+0xb7f/0x12d0 fs/reiserfs/stree.c:1462
 remove_save_link+0x30c/0x540 fs/reiserfs/super.c:540
 reiserfs_truncate_file+0x7ea/0xda0 fs/reiserfs/inode.c:2330
 reiserfs_setattr+0xa4d/0xf90 fs/reiserfs/inode.c:3409
 notify_change+0xd4d/0x1000 fs/attr.c:488
 do_truncate+0x21c/0x300 fs/open.c:65
 do_sys_ftruncate+0x2eb/0x390 fs/open.c:193
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f302bf0fae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007f30232700c8 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 00007f302c02f050 RCX: 00007f302bf0fae9
RDX: 0000000000000000 RSI: 0000000000000e5c RDI: 0000000000000004
RBP: 00007f302bf5b47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f302c02f050 R15: 00007ffea2eec738
 </TASK>

The buggy address belongs to the page:
page:ffffea00017999c0 refcount:2 mapcount:0 mapping:ffff888145cde6b0 index:0x214 pfn:0x5e667
memcg:ffff88807bef4000
aops:def_blk_aops ino:700001
flags: 0xfff00000002032(referenced|lru|active|private|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002032 ffffea00018661c8 ffffea0001786d48 ffff888145cde6b0
raw: 0000000000000214 ffff8880121dbae0 00000002ffffffff ffff88807bef4000
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 10953, ts 1434826801627, free_ts 1434809356071
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159
 __alloc_pages+0x272/0x700 mm/page_alloc.c:5421
 __page_cache_alloc+0xd4/0x4a0 mm/filemap.c:1022
 pagecache_get_page+0xa91/0x1010 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+0x22a/0xaf0 fs/buffer.c:1336
 sb_getblk include/linux/buffer_head.h:361 [inline]
 get_empty_nodes+0x8c1/0xd70 fs/reiserfs/fix_node.c:890
 fix_nodes+0x2615/0x8c70 fs/reiserfs/fix_node.c:2662
 reiserfs_insert_item+0xa7a/0xcb0 fs/reiserfs/stree.c:2240
 reiserfs_new_inode+0x11f9/0x1d90 fs/reiserfs/inode.c:2062
 reiserfs_create+0x3e3/0x6e0 fs/reiserfs/namei.c:668
 lookup_open fs/namei.c:3392 [inline]
 open_last_lookups fs/namei.c:3462 [inline]
 path_openat+0x12f6/0x2f20 fs/namei.c:3669
 do_filp_open+0x21c/0x460 fs/namei.c:3699
 do_sys_openat2+0x13b/0x500 fs/open.c:1211
 do_sys_open fs/open.c:1227 [inline]
 __do_sys_openat fs/open.c:1243 [inline]
 __se_sys_openat fs/open.c:1238 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1238
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
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+0xc34/0xcf0 mm/page_alloc.c:3317
 free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433
 release_pages+0x1bb9/0x1f40 mm/swap.c:963
 __pagevec_release+0x80/0xf0 mm/swap.c:983
 pagevec_release include/linux/pagevec.h:81 [inline]
 truncate_inode_pages_range+0x48b/0x1290 mm/truncate.c:329
 truncate_inode_pages mm/truncate.c:425 [inline]
 truncate_pagecache mm/truncate.c:735 [inline]
 truncate_setsize+0xcb/0xf0 mm/truncate.c:760
 reiserfs_setattr+0xa40/0xf90 fs/reiserfs/inode.c:3408
 notify_change+0xd4d/0x1000 fs/attr.c:488
 do_truncate+0x21c/0x300 fs/open.c:65
 do_sys_ftruncate+0x2eb/0x390 fs/open.c:193
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Memory state around the buggy address:
 ffff88805e667f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805e667f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805e668000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff88805e668080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805e668100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================