s3:passdb: Zero local memory in secrets_fetch()

Signed-off-by: Pavel Filipenský <pfilipensky@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>

diff --git a/source3/passdb/secrets.c b/source3/passdb/secrets.c
index c8390d5455e5ff02899430b078956969f6bc81a4..10692d6588b76e6d3f293afe73da515d15b22169 100644 (file)
--- a/source3/passdb/secrets.c
+++ b/source3/passdb/secrets.c
@@ -119,6 +119,16 @@ void *secrets_fetch(const char *key, size_t *size)
        if (result == NULL) {
                return NULL;
        }
+       /*
+        * secrets_fetch() is a generic code and may be used for sensitive data,
+        * so clear the local dbuf.dptr memory via BURN_PTR_SIZE().
+        * The future plan is to convert secrets_fetch() to talloc.
+        * That would improve performance via:
+        * - avoid smb_memdup() above, instead directly return dbuf.dptr
+        * - BURN_PTR_SIZE() will be done not here but in the caller and only
+        *   if the caller asks for sensitive data.
+        */
+       BURN_PTR_SIZE(dbuf.dptr, dbuf.dsize);
        TALLOC_FREE(dbuf.dptr);
 
        if (size) {