Re: [PATCH v2 1/4] contrib/vhost-user-blk: avoid g_return_val_if() input validation

[Marc-André Lureau]

On Wed, Dec 2, 2020 at 7:26 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>

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

---
 contrib/vhost-user-blk/vhost-user-blk.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/contrib/vhost-user-blk/vhost-user-blk.c b/contrib/vhost-user-blk/vhost-user-blk.c
index dc981bf945..60e3c9ed37 100644
--- a/contrib/vhost-user-blk/vhost-user-blk.c
+++ b/contrib/vhost-user-blk/vhost-user-blk.c
@@ -404,7 +404,11 @@ vub_get_config(VuDev *vu_dev, uint8_t *config, uint32_t len)
     VugDev *gdev;
     VubDev *vdev_blk;

-    g_return_val_if_fail(len <= sizeof(struct virtio_blk_config), -1);
+    if (len > sizeof(struct virtio_blk_config)) {
+        fprintf(stderr, "Invalid get_config len %u, expected <= %zu\n",
+                len, sizeof(struct virtio_blk_config));
+        return -1;
+    }

     gdev = container_of(vu_dev, VugDev, parent);
     vdev_blk = container_of(gdev, VubDev, parent);
--
2.28.0

--

Marc-André Lureau