[v5.15] KASAN: out-of-bounds Read in leaf_insert_into_buf

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: f6f7927ac664 Linux 5.15.127
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17dbf923a80000
kernel config: https://syzkaller.appspot.com/x/.config?x=ea39ec6ccd2c5d32
dashboard link: https://syzkaller.appspot.com/bug?extid=d2e9ff892c5b482d6bf8
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16e8deada80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1087bc65a80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/e290f46611c7/disk-f6f7927a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/64ee0ddb7c8c/vmlinux-f6f7927a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3c32675f93c1/bzImage-f6f7927a.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/35018481df5d/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d2e9ff...@syzkaller.appspotmail.com

REISERFS (device loop0): using 3.5.x disk format
REISERFS (device loop0): Created .reiserfs_priv - reserved for xattr storage.
==================================================================
BUG: KASAN: out-of-bounds in leaf_insert_into_buf+0x327/0x9a0 fs/reiserfs/lbalance.c:942
Read of size 372 at addr ffff88804a07ce8c by task syz-executor406/3486

CPU: 1 PID: 3486 Comm: syz-executor406 Not tainted 5.15.127-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
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
memmove+0x25/0x60 mm/kasan/shadow.c:54
leaf_insert_into_buf+0x327/0x9a0 fs/reiserfs/lbalance.c:942
leaf_item_bottle fs/reiserfs/lbalance.c:508 [inline]
leaf_copy_items fs/reiserfs/lbalance.c:617 [inline]
leaf_move_items+0x1bc1/0x28a0 fs/reiserfs/lbalance.c:726
balance_leaf_new_nodes_paste_whole fs/reiserfs/do_balan.c:1162 [inline]
balance_leaf_new_nodes_paste fs/reiserfs/do_balan.c:1215 [inline]
balance_leaf_new_nodes fs/reiserfs/do_balan.c:1246 [inline]
balance_leaf+0x6515/0x12510 fs/reiserfs/do_balan.c:1450
do_balance+0x309/0x8f0 fs/reiserfs/do_balan.c:1888
reiserfs_paste_into_item+0x73b/0x880 fs/reiserfs/stree.c:2159
reiserfs_get_block+0x226a/0x5390 fs/reiserfs/inode.c:1077
__block_write_begin_int+0x60b/0x1650 fs/buffer.c:2012
reiserfs_write_begin+0x346/0x810 fs/reiserfs/inode.c:2790
generic_cont_expand_simple+0x144/0x230 fs/buffer.c:2362
reiserfs_setattr+0x3ff/0xf90 fs/reiserfs/inode.c:3319
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: 0033:0x7efea1f57679
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 17 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff2e29a408 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 00007fff2e29a5d8 RCX: 00007efea1f57679
RDX: 00007efea1f57679 RSI: 0000000002007ffb RDI: 0000000000000005
RBP: 00007efea1fcb610 R08: 00007fff2e29a5d8 R09: 00007fff2e29a5d8
R10: 00007fff2e29a5d8 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff2e29a5c8 R14: 0000000000000001 R15: 0000000000000001
</TASK>

The buggy address belongs to the page:
page:ffffea0001281f00 refcount:1 mapcount:1 mapping:0000000000000000 index:0x7fffffffd pfn:0x4a07c
memcg:ffff888011e34000
anon flags: 0xfff00000080014(uptodate|lru|swapbacked|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000080014 ffffea000129fc08 ffffea0001281ec8 ffff8880196bd001
raw: 00000007fffffffd 0000000000000000 0000000100000000 ffff888011e34000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Movable, gfp_mask 0x1100cca(GFP_HIGHUSER_MOVABLE), pid 2949, ts 53274993701, free_ts 12298732275
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
alloc_pages_vma+0x39a/0x800 mm/mempolicy.c:2146
wp_page_copy+0x24e/0x2070 mm/memory.c:3026
handle_pte_fault mm/memory.c:4639 [inline]
__handle_mm_fault mm/memory.c:4756 [inline]
handle_mm_fault+0x2a3d/0x5950 mm/memory.c:4854
do_user_addr_fault arch/x86/mm/fault.c:1397 [inline]
handle_page_fault arch/x86/mm/fault.c:1485 [inline]
exc_page_fault+0x271/0x740 arch/x86/mm/fault.c:1541
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568
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+0x95/0x2d0 mm/page_alloc.c:3396
free_contig_range+0x95/0xf0 mm/page_alloc.c:9340
destroy_args+0xfe/0x97f mm/debug_vm_pgtable.c:1018
debug_vm_pgtable+0x40d/0x462 mm/debug_vm_pgtable.c:1331
do_one_initcall+0x22b/0x7a0 init/main.c:1295
do_initcall_level+0x157/0x207 init/main.c:1368
do_initcalls+0x49/0x86 init/main.c:1384
kernel_init_freeable+0x43c/0x5c5 init/main.c:1608
kernel_init+0x19/0x290 init/main.c:1499
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

Memory state around the buggy address:
ffff88804a07cd80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88804a07ce00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88804a07ce80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
^
ffff88804a07cf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88804a07cf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


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