From: Enric Balletbo i Serra enric.balletbo@collabora.com

[ Upstream commit 4eda776c3cefcb1f01b2d85bd8753f67606282b5 ]

'encoder' is dereferenced before it is null sanity checked, hence we potentially have a null pointer dereference bug. Instead, initialise drm_drv from encoder->dev->dev_private after we are sure 'encoder' is not null.

Fixes: 5182c1a556d7f ("drm/rockchip: add an common abstracted PSR driver") Cc: stable@vger.kernel.org Signed-off-by: Enric Balletbo i Serra enric.balletbo@collabora.com Signed-off-by: Heiko Stuebner heiko@sntech.de Link: https://patchwork.freedesktop.org/patch/msgid/20181013105654.11827-1-enric.b... Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- drivers/gpu/drm/rockchip/rockchip_drm_psr.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c index a553e182ff53..32e7dba2bf5e 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c @@ -221,13 +221,15 @@ EXPORT_SYMBOL(rockchip_drm_psr_flush_all); int rockchip_drm_psr_register(struct drm_encoder *encoder, void (*psr_set)(struct drm_encoder *, bool enable)) { - struct rockchip_drm_private *drm_drv = encoder->dev->dev_private; + struct rockchip_drm_private *drm_drv; struct psr_drv *psr; unsigned long flags;

if (!encoder || !psr_set) return -EINVAL;

+ drm_drv = encoder->dev->dev_private; + psr = kzalloc(sizeof(struct psr_drv), GFP_KERNEL); if (!psr) return -ENOMEM;