KASAN: out-of-bounds Read in leaf_paste_entries

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 31acccdc Linux 4.19.157
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16554be6500000
kernel config: https://syzkaller.appspot.com/x/.config?x=1f604e014c43fe09
dashboard link: https://syzkaller.appspot.com/bug?extid=7a1bd924e3172fd4cc0c
compiler: gcc (GCC) 10.1.0-syz 20200507

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7a1bd9...@syzkaller.appspotmail.com

REISERFS warning (device loop2): reiserfs_fill_super: You may need to run fsck or increase size of your LVM partition
REISERFS warning (device loop2): reiserfs_fill_super: Or may be you forgot to reboot after fdisk when it told you to
REISERFS (device loop1): Using rupasov hash to sort names
==================================================================
BUG: KASAN: out-of-bounds in memmove include/linux/string.h:388 [inline]
BUG: KASAN: out-of-bounds in leaf_paste_entries+0x417/0x910 fs/reiserfs/lbalance.c:1369
Read of size 18446744073709551601 at addr ffff8881f3158fc3 by task syz-executor.1/32491

CPU: 0 PID: 32491 Comm: syz-executor.1 Not tainted 4.19.157-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1fc/0x2fe lib/dump_stack.c:118
print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
kasan_report_error.cold+0x8a/0x1c7 mm/kasan/report.c:354
kasan_report+0x8f/0x96 mm/kasan/report.c:412
memmove+0x20/0x50 mm/kasan/kasan.c:293
memmove include/linux/string.h:388 [inline]
leaf_paste_entries+0x417/0x910 fs/reiserfs/lbalance.c:1369
balance_leaf_finish_node_paste_dirent fs/reiserfs/do_balan.c:1306 [inline]
balance_leaf_finish_node_paste fs/reiserfs/do_balan.c:1332 [inline]
balance_leaf_finish_node fs/reiserfs/do_balan.c:1375 [inline]
balance_leaf+0x8fb4/0xca40 fs/reiserfs/do_balan.c:1463
do_balance+0x306/0x760 fs/reiserfs/do_balan.c:1899
reiserfs_paste_into_item+0x636/0x7d0 fs/reiserfs/stree.c:2142
reiserfs_add_entry+0x89a/0xcc0 fs/reiserfs/namei.c:566
reiserfs_mkdir+0x66e/0x980 fs/reiserfs/namei.c:858
create_privroot fs/reiserfs/xattr.c:880 [inline]
reiserfs_xattr_init+0x406/0xae0 fs/reiserfs/xattr.c:1002
reiserfs_fill_super+0x206e/0x2ce4 fs/reiserfs/super.c:2180
mount_bdev+0x2fc/0x3b0 fs/super.c:1158
mount_fs+0xa3/0x30c fs/super.c:1261
vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
vfs_kern_mount fs/namespace.c:951 [inline]
do_new_mount fs/namespace.c:2469 [inline]
do_mount+0x113c/0x2f10 fs/namespace.c:2799
ksys_mount+0xcf/0x130 fs/namespace.c:3015
__do_sys_mount fs/namespace.c:3029 [inline]
__se_sys_mount fs/namespace.c:3026 [inline]
__x64_sys_mount+0xba/0x150 fs/namespace.c:3026
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x46090a
Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 ad 89 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 8a 89 fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007fc3c34bca88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fc3c34bcb20 RCX: 000000000046090a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fc3c34bcae0
RBP: 00007fc3c34bcae0 R08: 00007fc3c34bcb20 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020011500

The buggy address belongs to the page:
page:ffffea0007cc5600 count:3 mapcount:0 mapping:ffff8880b1afe4a0 index:0x213
flags: 0x57ff00000001044(referenced|active|private)
raw: 057ff00000001044 dead000000000100 dead000000000200 ffff8880b1afe4a0
raw: 0000000000000213 ffff888014ef32a0 00000003ffffffff ffff88823b2d08c0
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff88823b2d08c0

Memory state around the buggy address:
ffff8881f3158e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8881f3158f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8881f3158f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
^
ffff8881f3159000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8881f3159080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 13d2ce42 Linux 4.19.163
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1331ec2b500000
kernel config: https://syzkaller.appspot.com/x/.config?x=fac7c3360835a4e0

dashboard link: https://syzkaller.appspot.com/bug?extid=7a1bd924e3172fd4cc0c
compiler: gcc (GCC) 10.1.0-syz 20200507

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15314fb7500000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1393e1a3500000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7a1bd9...@syzkaller.appspotmail.com

reiserfs: using flush barriers
REISERFS (device loop0): journal params: device loop0, size 8192, 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 rupasov hash to sort names

==================================================================
BUG: KASAN: out-of-bounds in memmove include/linux/string.h:388 [inline]
BUG: KASAN: out-of-bounds in leaf_paste_entries+0x417/0x910 fs/reiserfs/lbalance.c:1369

Read of size 18446744073709551571 at addr ffff88808728ffe1 by task syz-executor854/8126

CPU: 0 PID: 8126 Comm: syz-executor854 Not tainted 4.19.163-syzkaller #0

RIP: 0033:0x447dda
Code: b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 7d a3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 5a a3 fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007ffd019408f8 EFLAGS: 00000297 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffd01940950 RCX: 0000000000447dda
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007ffd01940910
RBP: 00007ffd01940910 R08: 00007ffd01940950 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000007
R13: 0000000000000004 R14: 0000000000000003 R15: 0000000000000003

The buggy address belongs to the page:

page:ffffea00021ca3c0 count:3 mapcount:0 mapping:ffff88808ffa7be0 index:0x2013
flags: 0xfff00000001044(referenced|active|private)
raw: 00fff00000001044 dead000000000100 dead000000000200 ffff88808ffa7be0
raw: 0000000000002013 ffff88808b97dc78 00000003ffffffff ffff88823b2d08c0

page dumped because: kasan: bad access detected
page->mem_cgroup:ffff88823b2d08c0

Memory state around the buggy address:

ffff88808728fe80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88808728ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88808728ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
^
ffff888087290000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888087290080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================