2.1.12 segfault with ldap module

[Brian De Wolf]

While setting up freeradius recently, we noticed that it would segfault
on a restart after being used.  The segfault line would be something
like:
kernel: radiusd[2608]: segfault at 7feb7471f480 ip 00007feb7471f480 sp 00007fff451ea168 error 14 in libfreeradius-eap-2.1.12.so[7feb74d2b000+9000]

At first I thought this would be something in the eap module, but after
building a debug build and running it in gdb I got this backtrace:

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff3e0f480 in ?? ()
(gdb) bt
#0  0x00007ffff3e0f480 in ?? ()
#1  0x00007ffff71d9dea in ?? () from /usr/lib64/libcrypto.so.1.0.0
#2  0x00007ffff755a12d in SSL_free () from /usr/lib64/libssl.so.1.0.0
#3  0x00007ffff548b1da in ?? () from /usr/lib64/libldap_r-2.4.so.2
#4  0x00007ffff524df59 in ber_sockbuf_remove_io () from /usr/lib64/liblber-2.4.so.2
#5  0x00007ffff524dfed in ber_int_sb_destroy () from /usr/lib64/liblber-2.4.so.2
#6  0x00007ffff524e06c in ber_sockbuf_free () from /usr/lib64/liblber-2.4.so.2
#7  0x00007ffff546fb2c in ldap_ld_free () from /usr/lib64/libldap_r-2.4.so.2
#8  0x00007ffff56a50c0 in ldap_detach (instance=<value optimized out>) at rlm_ldap.c:2588
#9  0x00000000004186ce in module_instance_free (data=<value optimized out>) at modules.c:380
#10 0x00007ffff7bcee4d in FreeWalker (tree=0x796a50, X=0x799670) at rbtree.c:63
#11 0x00007ffff7bcee8e in rbtree_free (tree=0x9b14c0) at rbtree.c:74
#12 0x0000000000419450 in detach_modules () at modules.c:428
#13 0x000000000041d13c in main (argc=<value optimized out>, argv=<value optimized out>) at radiusd.c:456


After seeing that it looks like it's actually the ldap module causing
problems, I commented out all of my bits that use the ldap module and
it doesn't segfault on shutdown.  I also tried it with ldap but without
TLS enabled and it shut down clean still.


Has anyone seen this before?  Any solutions?  For the time being, I
guess I'll run the ldap module without TLS enabled.  Segfaults, even
benign ones, seem to get everyone antsy...