g_return_if_fail(), g_return_val_if_fail() misuse

[PATCH 1/2] backends/dbus-vmstate: Fix short read error handling

Posted by Markus Armbruster 4 years, 9 months ago

When dbus_vmstate_post_load() fails, it complains to stderr.  Except
on short read, where it checks with g_return_val_if_fail().  This
fails silently if G_DISABLE_CHECKS is undefined (it should be), or
else pads the short read with uninitialized bytes.

Replace g_return_val_if_fail() by a proper error check.

Fixes: 5010cec2bc87dafab39b3913c8ca91f88df9c540
Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 backends/dbus-vmstate.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/backends/dbus-vmstate.c b/backends/dbus-vmstate.c
index bd050e8e9c..2a0d2e4a31 100644
--- a/backends/dbus-vmstate.c
+++ b/backends/dbus-vmstate.c
@@ -229,7 +229,10 @@ static int dbus_vmstate_post_load(void *opaque, int version_id)
                                      &bytes_read, NULL, &err)) {
             goto error;
         }
-        g_return_val_if_fail(bytes_read == len, -1);
+        if (bytes_read != len) {
+            error_report("%s: Short read", __func__);
+            return -1;
+        }
         id[len] = 0;
 
         trace_dbus_vmstate_loading(id);
-- 
2.26.2

Re: [PATCH 1/2] backends/dbus-vmstate: Fix short read error handling

Posted by Marc-André Lureau 4 years, 9 months ago

On Tue, Jan 26, 2021 at 4:43 PM Markus Armbruster <armbru@redhat.com> wrote:
>
> When dbus_vmstate_post_load() fails, it complains to stderr.  Except
> on short read, where it checks with g_return_val_if_fail().  This
> fails silently if G_DISABLE_CHECKS is undefined (it should be), or
> else pads the short read with uninitialized bytes.
>
> Replace g_return_val_if_fail() by a proper error check.
>
> Fixes: 5010cec2bc87dafab39b3913c8ca91f88df9c540
> Signed-off-by: Markus Armbruster <armbru@redhat.com>

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

thanks

> ---
>  backends/dbus-vmstate.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/backends/dbus-vmstate.c b/backends/dbus-vmstate.c
> index bd050e8e9c..2a0d2e4a31 100644
> --- a/backends/dbus-vmstate.c
> +++ b/backends/dbus-vmstate.c
> @@ -229,7 +229,10 @@ static int dbus_vmstate_post_load(void *opaque, int version_id)
>                                       &bytes_read, NULL, &err)) {
>              goto error;
>          }
> -        g_return_val_if_fail(bytes_read == len, -1);
> +        if (bytes_read != len) {
> +            error_report("%s: Short read", __func__);
> +            return -1;
> +        }
>          id[len] = 0;
>
>          trace_dbus_vmstate_loading(id);
> --
> 2.26.2
>
>


-- 
Marc-André Lureau

Re: [PATCH 1/2] backends/dbus-vmstate: Fix short read error handling

Posted by Laurent Vivier 4 years, 8 months ago

Le 26/01/2021 à 13:42, Markus Armbruster a écrit :
> When dbus_vmstate_post_load() fails, it complains to stderr.  Except
> on short read, where it checks with g_return_val_if_fail().  This
> fails silently if G_DISABLE_CHECKS is undefined (it should be), or
> else pads the short read with uninitialized bytes.
> 
> Replace g_return_val_if_fail() by a proper error check.
> 
> Fixes: 5010cec2bc87dafab39b3913c8ca91f88df9c540
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>  backends/dbus-vmstate.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/backends/dbus-vmstate.c b/backends/dbus-vmstate.c
> index bd050e8e9c..2a0d2e4a31 100644
> --- a/backends/dbus-vmstate.c
> +++ b/backends/dbus-vmstate.c
> @@ -229,7 +229,10 @@ static int dbus_vmstate_post_load(void *opaque, int version_id)
>                                       &bytes_read, NULL, &err)) {
>              goto error;
>          }
> -        g_return_val_if_fail(bytes_read == len, -1);
> +        if (bytes_read != len) {
> +            error_report("%s: Short read", __func__);
> +            return -1;
> +        }
>          id[len] = 0;
>  
>          trace_dbus_vmstate_loading(id);
> 

Applied to my trivial-patches branch.

Thanks,
Laurent