lib-ntlm: Ensure data_size is large enough for buffer

diff --git a/src/lib-ntlm/ntlm-message.c b/src/lib-ntlm/ntlm-message.c
index 65dcfdfdbfe27f3f10589a7843efdebba388c182..d1aef0f6a06c4132c613a4ebeb47e742c283803d 100644 (file)
--- a/src/lib-ntlm/ntlm-message.c
+++ b/src/lib-ntlm/ntlm-message.c
@@ -176,6 +176,11 @@ ntlmssp_create_challenge(pool_t pool, const struct ntlmssp_request *request,
 static bool ntlmssp_check_buffer(const struct ntlmssp_buffer *buffer,
                                 size_t data_size, const char **error)
 {
+       if (data_size < sizeof(*buffer)) {
+               *error = "data_size is smaller than buffer header";
+               return FALSE;
+       }
+
        uint32_t offset = le32_to_cpu(buffer->offset);
        uint16_t length = le16_to_cpu(buffer->length);
        uint16_t space = le16_to_cpu(buffer->space);