snmpd(8): fix use of uninitialized pointer

[Jan Klemkow]

Hi,

The following diff fixes the use of the uninitialized pointer iter
in trapcmd_exec().

iter is just initialized in traphandler_parse() if vers is SNMP_V2.  In
all other cases iter stays uninitialized and may dereferenced in
trapcmd_exec().

OK?

bye,
Jan

Index: traphandler.c
===================================================================
RCS file: /cvs/src/usr.sbin/snmpd/traphandler.c,v
retrieving revision 1.15
diff -u -p -r1.15 traphandler.c
--- traphandler.c       24 Oct 2019 12:39:27 -0000      1.15
+++ traphandler.c       9 Mar 2020 21:59:56 -0000
@@ -305,7 +305,7 @@ traphandler_fork_handler(struct privsep_
        struct sockaddr         *sa;
        char                    *buf;
        ssize_t                  n;
-       struct ber_element      *req, *iter;
+       struct ber_element      *req, *iter = NULL;
        struct trapcmd          *cmd;
        struct ber_oid           trapoid;
        u_int                    uptime;