drm/tegra: put drm_gem_object ref on error in tegra_fb_create

Inside tegra_fb_create(), drm_gem_object_lookup() increments ref count of
the found object. But if the following size check fails then the last
found object's ref count should be put there as the unreferencing loop
can't detect this situation.

Found by Linux Verification Center (linuxtesting.org).

Fixes: de2ba664c30f ("gpu: host1x: drm: Add memory manager and fb")
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231215093356.12067-1-pchelkin@ispras.ru

diff --git a/drivers/gpu/drm/tegra/fb.c b/drivers/gpu/drm/tegra/fb.c
index a719af1dc9a573af54ad951b1c6e1e115ec0f00c..46170753699dc0e71224ba52654b21328af9804e 100644 (file)
--- a/drivers/gpu/drm/tegra/fb.c
+++ b/drivers/gpu/drm/tegra/fb.c
@@ -159,6 +159,7 @@ struct drm_framebuffer *tegra_fb_create(struct drm_device *drm,
 
                if (gem->size < size) {
                        err = -EINVAL;
+                       drm_gem_object_put(gem);
                        goto unreference;
                }