bisecting fixing commit since 2c8a3fceddf0dd87f278e7a5e01350f86f844b1c
building syzkaller on 98682e5e2aefc9aad61354f4f3ac93be96002a2a
testing commit 2c8a3fceddf0dd87f278e7a5e01350f86f844b1c with gcc (GCC) 8.4.1 20210217
kernel signature: cfcd8c966c050b40e1898e202dca2e8a9b407445a24b43b76d04f466f5aa40c5
all runs: crashed: KASAN: out-of-bounds Read in leaf_paste_entries
testing current HEAD 670d6552eda8ff0c5f396d3d6f0174237917c66c
testing commit 670d6552eda8ff0c5f396d3d6f0174237917c66c with gcc (GCC) 8.4.1 20210217
kernel signature: 854342b8622e60364fef64e7e6a0df383ca5f0b35e4845111e43a61f505525aa
all runs: crashed: KASAN: out-of-bounds Read in leaf_paste_entries
revisions tested: 2, total time: 22m12.225379424s (build: 15m9.699610918s, test: 6m28.5319431s)
the crash still happens on HEAD
commit msg: Linux 4.14.227
crash: KASAN: out-of-bounds Read in leaf_paste_entries
IPv6: ADDRCONF(NETDEV_UP): veth1_to_batadv: link is not ready
REISERFS (device loop2): Using tea hash to sort names
==================================================================
device veth1_vlan entered promiscuous mode
BUG: KASAN: out-of-bounds in memmove include/linux/string.h:391 [inline]
BUG: KASAN: out-of-bounds in leaf_paste_entries+0x3f9/0xa20 fs/reiserfs/lbalance.c:1378
Read of size 18446744073709551584 at addr ffff88807b18dfa4 by task syz-executor.2/9613

CPU: 0 PID: 9613 Comm: syz-executor.2 Not tainted 4.14.227-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x14b/0x1e7 lib/dump_stack.c:58
 print_address_description.cold.6+0x9/0x1ca mm/kasan/report.c:252
IPv6: ADDRCONF(NETDEV_UP): veth0_macvtap: link is not ready
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold.7+0x11a/0x2d3 mm/kasan/report.c:393
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13c/0x1b0 mm/kasan/kasan.c:267
 memmove+0x23/0x50 mm/kasan/kasan.c:293
 memmove include/linux/string.h:391 [inline]
 leaf_paste_entries+0x3f9/0xa20 fs/reiserfs/lbalance.c:1378
 balance_leaf_finish_node_paste_dirent fs/reiserfs/do_balan.c:1306 [inline]
 balance_leaf_finish_node_paste.isra.15+0x49b/0x12c0 fs/reiserfs/do_balan.c:1332
 balance_leaf_finish_node fs/reiserfs/do_balan.c:1375 [inline]
 balance_leaf fs/reiserfs/do_balan.c:1463 [inline]
 do_balance+0x25dc/0x6c30 fs/reiserfs/do_balan.c:1899
IPv6: ADDRCONF(NETDEV_UP): veth1_macvtap: link is not ready
 reiserfs_paste_into_item+0x4ad/0x5e0 fs/reiserfs/stree.c:2148
 reiserfs_add_entry+0x772/0xb30 fs/reiserfs/namei.c:566
 reiserfs_mkdir+0x586/0x820 fs/reiserfs/namei.c:858
 xattr_mkdir.constprop.6+0x80/0xc0 fs/reiserfs/xattr.c:76
 create_privroot fs/reiserfs/xattr.c:880 [inline]
 reiserfs_xattr_init+0x35f/0xa10 fs/reiserfs/xattr.c:1002
 reiserfs_fill_super+0x19a3/0x26f0 fs/reiserfs/super.c:2180
 mount_bdev+0x26f/0x330 fs/super.c:1134
 get_super_block+0x10/0x20 fs/reiserfs/super.c:2609
 mount_fs+0x7f/0x270 fs/super.c:1237
 vfs_kern_mount.part.9+0x58/0x3c0 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0x352/0x2af0 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xb1/0xd0 fs/namespace.c:3072
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x4672ba
RSP: 002b:00007fe9cd167fa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00000000004672ba
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fe9cd168000
RBP: 00007fe9cd168040 R08: 00007fe9cd168040 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000000
R13: 0000000020000100 R14: 00007fe9cd168000 R15: 00000000200003c0

The buggy address belongs to the page:
page:ffffea0001ec6340 count:5 mapcount:0 mapping:ffff8880b19434e8 index:0x3d97
flags: 0xfff00000001024(referenced|lru|private)
raw: 00fff00000001024 ffff8880b19434e8 0000000000003d97 00000005ffffffff
raw: ffffea0001ec5c60 ffffea0001ebda20 ffff888084fab000 ffff8880b5fd4a00
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff8880b5fd4a00

Memory state around the buggy address:
 ffff88807b18de80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88807b18df00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88807b18df80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                               ^
 ffff88807b18e000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88807b18e080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================