4582. [security] 'rndc ""' could trigger a assertion failure in named.

(CVE-2017-3138) [RT #44924]

CHANGES

@@ -1,3 +1,6 @@
+4582.	[security]	'rndc ""' could trigger a assertion failure in named.
+			(CVE-2017-3138) [RT #44924]
+
 4581.	[port]		Linux: Add getpid and getrandom to the list of system
 			calls named uses for seccomp. [RT #44883]
 

bin/tests/system/rndc/tests.sh

@@ -566,5 +566,13 @@ EOF
     status=`expr $status + $ret`
 fi
 
+n=`expr $n + 1`
+echo "I:check 'rndc \"\"' is handled ($n)"
+ret=0
+$RNDCCMD "" > rndc.out.test$n 2>&1 && ret=1
+grep "rndc: '' failed: failure" rndc.out.test$n > /dev/null
+if [ $ret != 0 ]; then echo "I:failed"; fi
+status=`expr $status + $ret`
+
 echo "I:exit status: $status"
 [ $status -eq 0 ] || exit 1

lib/isc/include/isc/lex.h

@@ -145,8 +145,6 @@ isc_lex_create(isc_mem_t *mctx, size_t max_token, isc_lex_t **lexp);
  * Requires:
  *\li	'*lexp' is a valid lexer.
  *
- *\li	max_token > 0.
- *
  * Ensures:
  *\li	On success, *lexp is attached to the newly created lexer.
  *

lib/isc/lex.c

@@ -86,9 +86,10 @@ isc_lex_create(isc_mem_t *mctx, size_t max_token, isc_lex_t **lexp) {
 	/*
 	 * Create a lexer.
 	 */
-
 	REQUIRE(lexp != NULL && *lexp == NULL);
-	REQUIRE(max_token > 0U);
+
+	if (max_token == 0U)
+		max_token = 1;
 
 	lex = isc_mem_get(mctx, sizeof(*lex));
 	if (lex == NULL)