CVE-2022-32745 s4/dsdb/samldb: Check for empty values array

This avoids potentially trying to access the first element of an empty
array.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15008

Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>

diff --git a/source4/dsdb/samdb/ldb_modules/samldb.c b/source4/dsdb/samdb/ldb_modules/samldb.c
index 107e643e49268e5ef83672b6a7c1e081831d1ef2..3625bb42e58d1f3bb1336b68f917e5e831dd6dfc 100644 (file)
--- a/source4/dsdb/samdb/ldb_modules/samldb.c
+++ b/source4/dsdb/samdb/ldb_modules/samldb.c
@@ -751,7 +751,7 @@ static int samldb_schema_add_handle_linkid(struct samldb_ctx *ac)
                return ret;
        }
 
-       if (el == NULL) {
+       if (el == NULL || el->num_values == 0) {
                return LDB_SUCCESS;
        }
 
@@ -919,7 +919,7 @@ static int samldb_schema_add_handle_mapiid(struct samldb_ctx *ac)
                return ret;
        }
 
-       if (el == NULL) {
+       if (el == NULL || el->num_values == 0) {
                return LDB_SUCCESS;
        }