On Mon, Sep 05, 2016 at 05:44:57PM +0200, Johannes Schindelin wrote: > The problem with that: mmap()ed memory is *not* NUL-terminated, yet the > pickaxe code calls regexec() on it just the same. > > This problem has been reported by my colleague Chris Sidi. > > Please note that this patch series is a hot fix I applied to Git for > Windows (the bug does not trigger a segmentation fault for me on Linux, > strangely enough, but it is really a problem on Windows). This has come up before, and I think somebody mentioned that on Linux, you are OK unless the buffer ends right at a page boundary (i.e., the buffer size is a multiple of the page size). I don't know if that's true or not. > So at least I have a workaround in place. Ideally, though, we would > NUL-terminate the buffers only when needed, or somehow call regexec() on > ptr/size parameters instead of passing a supposedly NUL-terminated > string to it? There's some discussion in: http://public-inbox.org/git/20121030121747.GA4231@xxxxxxxxxxxxxxxxxxxxx/#r and the thread below it. The quickest way to fix regexec() would be to have everybody use the built-in GNU regex in compat/. People seemed somewhat positive on that direction, but we never followed up. -Peff