[PATCH 5.0 054/101] drm/tegra: hub: Fix dereference before check

From: Greg Kroah-Hartman
Date: Thu May 02 2019 - 11:31:11 EST


[ Upstream commit 7cf77b273a8fc51e7de622fa6691abd4436a9a6b ]

Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
Signed-off-by: Sasha Levin (Microsoft) <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/tegra/hub.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/tegra/hub.c b/drivers/gpu/drm/tegra/hub.c
index 922a48d5a483..c7c612579270 100644
--- a/drivers/gpu/drm/tegra/hub.c
+++ b/drivers/gpu/drm/tegra/hub.c
@@ -378,14 +378,16 @@ static int tegra_shared_plane_atomic_check(struct drm_plane *plane,
static void tegra_shared_plane_atomic_disable(struct drm_plane *plane,
struct drm_plane_state *old_state)
{
- struct tegra_dc *dc = to_tegra_dc(old_state->crtc);
struct tegra_plane *p = to_tegra_plane(plane);
+ struct tegra_dc *dc;
u32 value;

/* rien ne va plus */
if (!old_state || !old_state->crtc)
return;

+ dc = to_tegra_dc(old_state->crtc);
+
/*
* XXX Legacy helpers seem to sometimes call ->atomic_disable() even
* on planes that are already disabled. Make sure we fallback to the
--
2.19.1