Crash in proxy authorization in some case (ITS#2578)

[emmanuel.duru@atosorigin.com]

Full_Name: Emmanuel Duru
Version: 2.2.0 alpha
OS: solaris 8
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (195.68.44.148)


My server is configured with sasl-authz-policy = both.
I have one entry (user A) with a saslAuthzTo set to another entry dname (user
B).
I run ldapsearch in the name of user A, trying proxy authorization to user C.
The server crashes.
Proposed correction : in saslauthz.c:slap_sasl_check_authz(), test the nullity
of the vals variable set by backend_attribute() before the loop for (i=0,... ?