Question about CVE-2014-7912

[AC Question]

This problem was fixed in 2014, but i really cannot understand the fix. I need someone to be able to explain in to me, on what was really fixed. The faulty code and fixed code is here: h t tp s ://android-review.googlesource.com/#/c/138951/1/dhcp.c

would really appreciate if somebody could explain it to me a little