UserAgent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.133 Safari/537.36

Steps to reproduce the problem:
https://chromium.googlesource.com/chromium/src.git/+/59.0.3067.2/third_party/libxml/src/dict.c

the vulnerability present in the dict.c file in xmlDictLookup function. 

xmlDictLookup function has 3 parameters and xmlDictPtr dict, const xmlChar *name, int len. And in the https://chromium.googlesource.com/chromium/src.git/+/59.0.3067.2/third_party/libxml/src/dict.c#839

don't checked this
len > strlen((const char *) name)
condition

```
root@ubuntu:/home/vah13/Desktop/libxml-cpp-wrapper# valgrind --leak-check=full --show-leak-kinds=all  ./uri_h in/textfile.txt 
==6206== Memcheck, a memory error detector
==6206== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==6206== Using Valgrind-3.10.1 and LibVEX; rerun with -h for copyright info
==6206== Command: ./uri_h in/textfile.txt
==6206== 
==6206== Invalid read of size 1
==6206==    at 0x402D3F3: strlen (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==6206==    by 0x8048D56: main (writer.cpp:72)
==6206==  Address 0x49651f1 is 0 bytes after a block of size 1 alloc'd
==6206==    at 0x402A6DC: operator new(unsigned int) (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==6206==    by 0x8048D43: main (writer.cpp:30)
==6206== 
==6206== Invalid read of size 1
==6206==    at 0x458D0DC: xmlDictComputeFastKey (dict.c:451)
==6206==    by 0x458D0DC: xmlDictLookup (dict.c:851)
==6206==    by 0x8048D73: main (writer.cpp:72)
==6206==  Address 0x49861e1 is 132,273 bytes inside an unallocated block of size 4,190,904 in arena "client"
==6206== 
==6206== Invalid read of size 1
==6206==    at 0x458D11C: xmlDictComputeFastKey (dict.c:455)
==6206==    by 0x458D11C: xmlDictLookup (dict.c:851)
==6206==    by 0x8048D73: main (writer.cpp:72)
==6206==  Address 0x49651f9 is 8 bytes after a block of size 1 alloc'd
==6206==    at 0x402A6DC: operator new(unsigned int) (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==6206==    by 0x8048D43: main (writer.cpp:30)

```

for the fix, I think, need change code like this 
src.git/+/59.0.3067.2/third_party/libxml/src/dict.c#839
```
xmlDictLookup(xmlDictPtr dict, const xmlChar *name, int len) {
    unsigned long key, okey, nbi = 0;
    xmlDictEntryPtr entry;
    xmlDictEntryPtr insert;
    const xmlChar *ret;
    unsigned int l;

    if ((dict == NULL) || (name == NULL))
        return(NULL);

--    if (len < 0)
++    if (len < 0 || len > strlen((const char *) name))
        l = strlen((const char *) name);
    else
        l = len;

    if (((dict->limit > 0) && (l >= dict->limit)) ||
        (l > INT_MAX / 2))
        return(NULL);

    /*
     * Check for duplicate and insertion location.
     */
    okey = xmlDictComputeKey(dict, name, l);

```

What is the expected behavior?

What went wrong?
I reported information about this bug to bugzilla.gnome.org 

https://bugzilla.gnome.org/show_bug.cgi?id=781120

Did this work before? No 

Does this work in other browsers? N/A

Chrome version: 57.0.2987.133  Channel: stable
OS Version: 6.1 (Windows 7, Windows Server 2008 R2)
Flash Version: Shockwave Flash 25.0 r0