From: Jeremy Allison <jra@samba.org>
Date: Tue, 9 Jun 2015 19:42:10 +0000 (-0700)
Subject: CVE-2015-3223: lib: ldb: Cope with canonicalise_fn returning string "", length 0.
X-Git-Tag: samba-4.1.22~18
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fb456954f332c07a645226d59b3b00ec252f8b26;p=thirdparty%2Fsamba.git

CVE-2015-3223: lib: ldb: Cope with canonicalise_fn returning string "", length 0.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11325

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
---

diff --git a/lib/ldb/common/ldb_match.c b/lib/ldb/common/ldb_match.c
index 7918aec65f1..8bdb0e19b16 100644
--- a/lib/ldb/common/ldb_match.c
+++ b/lib/ldb/common/ldb_match.c
@@ -270,6 +270,14 @@ static int ldb_wildcard_compare(struct ldb_context *ldb,
 		if (cnk.length > val.length) {
 			goto mismatch;
 		}
+		/*
+		 * Empty strings are returned as length 0. Ensure
+		 * we can cope with this.
+		 */
+		if (cnk.length == 0) {
+			goto mismatch;
+		}
+
 		if (memcmp((char *)val.data, (char *)cnk.data, cnk.length) != 0) goto mismatch;
 		val.length -= cnk.length;
 		val.data += cnk.length;
@@ -283,7 +291,13 @@ static int ldb_wildcard_compare(struct ldb_context *ldb,
 		chunk = tree->u.substring.chunks[c];
 		if(a->syntax->canonicalise_fn(ldb, ldb, chunk, &cnk) != 0) goto mismatch;
 
-		/* FIXME: case of embedded nulls */
+		/*
+		 * Empty strings are returned as length 0. Ensure
+		 * we can cope with this.
+		 */
+		if (cnk.length == 0) {
+			goto mismatch;
+		}
 		p = strstr((char *)val.data, (char *)cnk.data);
 		if (p == NULL) goto mismatch;
 		if ( (! tree->u.substring.chunks[c + 1]) && (! tree->u.substring.end_with_wildcard) ) {