pcre_exec crashes for some regular expressions about vanitygen

[WyseNynja]

What pattern is that supposed to match?

[wladston]

This pattern is just a simplest crash sample, it's supposed to match anything. One interesting pattern that crashes on the same bug is this one

^1(.)(.)(.)(.).?\4\3\2\1[1].*$

It would match an address that starts with a palindrome word.

[WyseNynja]

^1....*$ works fine

[wladston]

Yes, but in order to do complex matchings (such as the palindrome), groups (the parenthesis) are required.