Cast zlib malloc size to size_t before multiply.

src/common/files.c

@@ -973,7 +973,7 @@ static int check_header_coherency(FILE *fp, packfile_t *entry)
 
 static voidpf FS_zalloc(voidpf opaque, uInt items, uInt size)
 {
-    return FS_Malloc(items * size);
+    return FS_Malloc((size_t)items * size);
 }
 
 static void FS_zfree(voidpf opaque, voidpf address)

src/server/main.c

@@ -2152,7 +2152,7 @@ static void sv_hostname_changed(cvar_t *self)
 #if USE_ZLIB
 voidpf SV_zalloc(voidpf opaque, uInt items, uInt size)
 {
-    return SV_Malloc(items * size);
+    return SV_Malloc((size_t)items * size);
 }
 
 void SV_zfree(voidpf opaque, voidpf address)

src/server/mvd/client.c

@@ -1100,7 +1100,7 @@ static void send_stream_stop(gtv_t *gtv)
 #if USE_ZLIB
 static voidpf gtv_zalloc(voidpf opaque, uInt items, uInt size)
 {
-    return MVD_Malloc(items * size);
+    return MVD_Malloc((size_t)items * size);
 }
 
 static void gtv_zfree(voidpf opaque, voidpf address)