Re: [PATCH v2 3/4] contrib/vhost-user-input: avoid g_return_val_if() input validation

[Marc-André Lureau]

On Wed, Dec 2, 2020 at 7:27 PM Stefan Hajnoczi <stefanha@redhat.com> wrote:

Do not validate input with g_return_val_if(). This API is intended for
checking programming errors and is compiled out with -DG_DISABLE_CHECKS.

Use an explicit if statement for input validation so it cannot
accidentally be compiled out.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 contrib/vhost-user-input/main.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/contrib/vhost-user-input/main.c b/contrib/vhost-user-input/main.c
index 6020c6f33a..1d79c61200 100644
--- a/contrib/vhost-user-input/main.c
+++ b/contrib/vhost-user-input/main.c
@@ -212,7 +212,11 @@ static int vi_get_config(VuDev *dev, uint8_t *config, uint32_t len)
 {
     VuInput *vi = container_of(dev, VuInput, dev.parent);

-    g_return_val_if_fail(len <= sizeof(*vi->sel_config), -1);
+    if (len > sizeof(*vi->sel_config)) {
+        g_critical("%s: len %u is larger than %zu",
+                   __func__, len, sizeof(*vi->sel_config));
+        return -1;

g_critical() already has __FILE__ __LINE__ and G_STRFUNC.

otherwise looks good:

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

 

+    }

     if (vi->sel_config) {
         memcpy(config, vi->sel_config, len);
--
2.28.0

--

Marc-André Lureau