CVE-2009-0845 SPNEGO can dereference a null pointer

acc_ctx_new() can return an error condition without establishing a
SPNEGO context structure.  This can cause a null pointer dereference
in cleanup code in spnego_gss_accept_sec_context().

ticket: 6417
tags: pullup
target_version: 1.7

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@22084 dc483132-0cff-0310-8789-dd5450dbe970

diff --git a/src/lib/gssapi/spnego/spnego_mech.c b/src/lib/gssapi/spnego/spnego_mech.c
index 3a6653caf08a0e7273ce5260e5a6afe1154c12f8..708017a8d32b9916a063c16bc69cc2c2a922d720 100644 (file)
--- a/src/lib/gssapi/spnego/spnego_mech.c
+++ b/src/lib/gssapi/spnego/spnego_mech.c
@@ -1650,7 +1650,8 @@ spnego_gss_accept_sec_context(
                                 &negState, &return_token);
        }
 cleanup:
-       if (return_token != NO_TOKEN_SEND && return_token != CHECK_MIC) {
+       if (return_token == INIT_TOKEN_SEND ||
+           return_token == CONT_TOKEN_SEND) {
                /* For acceptor-sends-first send a tokenInit */
                int tmpret;