Re: Segfault

[William Ahern <william@...>]

On Sun, Sep 08, 2013 at 10:24:12PM +0200, Chris Datfung wrote:
> On Sun, Sep 8, 2013 at 5:20 PM, Chris Datfung <chris.datfung@gmail.com>wrote:
> 
> > On Tue, Sep 3, 2013 at 9:33 PM, William Ahern <william@25thandclement.com>wrote:
> >
> >>
> >>  # service=0xfffffffd <Address 0xfffffffd out of bounds>, port=62352) at
> >>  # tcp_unix.c:166
> >>
> >> A little Googling suggests that _this_ tcp_open call comes from c-client,
> >> the UW-IMAP library. Perhaps the issue is as kamicc olo suggested.
> >>
> >
> >
> Just to close the loop on this. The issue occurred on a CentOS server
> running cPanel and EasyApache. I rebuilt PHP without IMAP support which
> solved the problem. I'm still curious what led you to know that this was
> related to IMAP under PHP.
> 

The backtrace you posted on pastebin.com didn't match the code in luasocket.
So I Google'd tcp_open with some other routines in that backtrace triggered
by tcp_open and got hits for c-client. I downloaded the c-client code and
compared the call chain, and it was a match.

I noticed in the backtrace the entry points for Apache--ap_* and
modsecurity_*. It was just an educated guess that it was PHP; it's widely
used and often installed by default.