drm: check return values in drm_version

In drm_version, actually check the results from function calls so that
we're not potentially passing garbage back to userspace.

Signed-off-by: Andres Salomon <dilinger@collabora.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 11 insertions, 5 deletions

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index ec0e3ae8c09d..5bd3f9461e2d 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -403,15 +403,21 @@ static int drm_version(struct drm_device *dev, void *data,
                        struct drm_file *file_priv)
 {
         struct drm_version *version = data;
+        int err;
 
         version->version_major = dev->driver->major;
         version->version_minor = dev->driver->minor;
         version->version_patchlevel = dev->driver->patchlevel;
-        drm_copy_field(version->name, &version->name_len, dev->driver->name);
-        drm_copy_field(version->date, &version->date_len, dev->driver->date);
-        drm_copy_field(version->desc, &version->desc_len, dev->driver->desc);
-
-        return 0;
+        err = drm_copy_field(version->name, &version->name_len,
+                        dev->driver->name);
+        if (!err)
+                err = drm_copy_field(version->date, &version->date_len,
+                                dev->driver->date);
+        if (!err)
+                err = drm_copy_field(version->desc, &version->desc_len,
+                                dev->driver->desc);
+
+        return err;
 }
 
 /**