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>
---
 block/export/vhost-user-blk-server.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/block/export/vhost-user-blk-server.c b/block/export/vhost-user-blk-server.c
index 62672d1cb9..bccbc98d57 100644
--- a/block/export/vhost-user-blk-server.c
+++ b/block/export/vhost-user-blk-server.c
@@ -267,7 +267,11 @@ vu_blk_get_config(VuDev *vu_dev, uint8_t *config, uint32_t len)
     VuServer *server = container_of(vu_dev, VuServer, vu_dev);
     VuBlkExport *vexp = container_of(server, VuBlkExport, vu_server);
 
-    g_return_val_if_fail(len <= sizeof(struct virtio_blk_config), -1);
+    if (len > sizeof(struct virtio_blk_config)) {
+        error_report("Invalid get_config len %u, expected <= %zu",
+                     len, sizeof(struct virtio_blk_config));
+        return -1;
+    }
 
     memcpy(config, &vexp->blkcfg, len);
     return 0;
-- 
2.28.0

On 12/2/20 4:26 PM, Stefan Hajnoczi 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>
> ---
>  block/export/vhost-user-blk-server.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

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>
>

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

---
>  block/export/vhost-user-blk-server.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/block/export/vhost-user-blk-server.c
> b/block/export/vhost-user-blk-server.c
> index 62672d1cb9..bccbc98d57 100644
> --- a/block/export/vhost-user-blk-server.c
> +++ b/block/export/vhost-user-blk-server.c
> @@ -267,7 +267,11 @@ vu_blk_get_config(VuDev *vu_dev, uint8_t *config,
> uint32_t len)
>      VuServer *server = container_of(vu_dev, VuServer, vu_dev);
>      VuBlkExport *vexp = container_of(server, VuBlkExport, vu_server);
>
> -    g_return_val_if_fail(len <= sizeof(struct virtio_blk_config), -1);
> +    if (len > sizeof(struct virtio_blk_config)) {
> +        error_report("Invalid get_config len %u, expected <= %zu",
> +                     len, sizeof(struct virtio_blk_config));
> +        return -1;
> +    }
>
>      memcpy(config, &vexp->blkcfg, len);
>      return 0;
> --
> 2.28.0
>
>

-- 
Marc-André Lureau