Paul Oehler wrote:
We're seeing vchkpw segfault seemingly at random during pop3
authentication, but only on CentOS 5 x86_64. The result is pop3
authentication failing randomly. CentOS 5 32 bit and CentOS 4 64 and 32
bit do not exhibit this behavior, with the same vpopmail code base
(5.4.9). This is admittidly not the newest vpopmail version - does this
problem sound familiar to anyone and do you recall it being fixed in one
of the newer versions?
It appears to be related to the "softlimit" command that is used in the
invocation of pop3. Attempting to raise the softlimit -m parameter to
very high values (as high as 512000000) does not prevent the segfault,
however, removing the softlimit line entirely does prevent the
segfaults. Also, copying the vchkpw binary compiled on a 32 bit CentOS
5 OS to the 64 bit install also "fixes" the problem.
I realize 5.4.9 is pretty old, but we don't require many of the new
features in the newer vpopmail releases, and would prefer to not have to
recompile qmail-smtpd if we can get away with it (where we're using
In the ChangeLog for 5.4.10 I see this:
- md5.h: fix related to segfaults in vchkpw on Sparc64. 
What's the likelyhood that is related?
You might want to try recompiling everything with out any compiler
optimization flags like -O or -O2.
We've seen some 64 bit systems have problems if -OX is enabled.
With the -O options removed and everything recompiled the problems went
Hope that helps,