[PATCH] selinux: fix compute_av bug

From: Stephen Smalley <sds@epoch.ncsc.mil>

This patch fixes a bug in the SELinux compute_av code; the current code
yields the right access computation but can cause unnecessary (but
harmless) processing to occur when transition permission wasn't granted in
the first place by the TE configuration.  Thanks to Chad Hanson of TCS for
reporting the bug.

security/selinux/ss/services.c

@@ -262,7 +262,7 @@ static int context_struct_compute_av(struct context *scontext,
 	 * pair.
 	 */
 	if (tclass == SECCLASS_PROCESS &&
-	    avd->allowed && PROCESS__TRANSITION &&
+	    (avd->allowed & PROCESS__TRANSITION) &&
 	    scontext->role != tcontext->role) {
 		for (ra = policydb.role_allow; ra; ra = ra->next) {
 			if (scontext->role == ra->role &&