[PATCH 5.5 139/399] gpu/drm: ingenic: Avoid null pointer deference in plane atomic update

Greg Kroah-Hartman
2020-02-21T08:46:33Z

From: Paul Cercueil <paul@crapouillou.net>

[ Upstream commit 354b051c5dcbeb35bbfd5d54161364fc7a75a58a ]

It is possible that there is no drm_framebuffer associated with a given
plane state.

v2: Handle drm_plane->state which can be NULL too

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20191210144142.33143-2-paul@crapouillou.net
# *** extracted tags ***
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/ingenic/ingenic-drm.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/ingenic/ingenic-drm.c b/drivers/gpu/drm/ingenic/ingenic-drm.c
index ec32e1c673350..43a015f33e975 100644
--- a/drivers/gpu/drm/ingenic/ingenic-drm.c
+++ b/drivers/gpu/drm/ingenic/ingenic-drm.c
@@ -372,14 +372,18 @@ static void ingenic_drm_plane_atomic_update(struct drm_plane *plane,
struct ingenic_drm *priv = drm_plane_get_priv(plane);
struct drm_plane_state *state = plane->state;
unsigned int width, height, cpp;
+ dma_addr_t addr;

- width = state->crtc->state->adjusted_mode.hdisplay;
- height = state->crtc->state->adjusted_mode.vdisplay;
- cpp = state->fb->format->cpp[plane->index];
+ if (state && state->fb) {
+ addr = drm_fb_cma_get_gem_addr(state->fb, state, 0);
+ width = state->crtc->state->adjusted_mode.hdisplay;
+ height = state->crtc->state->adjusted_mode.vdisplay;
+ cpp = state->fb->format->cpp[plane->index];

- priv->dma_hwdesc->addr = drm_fb_cma_get_gem_addr(state->fb, state, 0);
- priv->dma_hwdesc->cmd = width * height * cpp / 4;
- priv->dma_hwdesc->cmd |= JZ_LCD_CMD_EOF_IRQ;
+ priv->dma_hwdesc->addr = addr;
+ priv->dma_hwdesc->cmd = width * height * cpp / 4;
+ priv->dma_hwdesc->cmd |= JZ_LCD_CMD_EOF_IRQ;
+ }
}

static void ingenic_drm_encoder_atomic_mode_set(struct drm_encoder *encoder,
--
2.20.1