9ac69bda79
[ Upstream commit 2e63972a2de14482d0eae1a03a73e379f1c3f44c ] The variable crtc->state->event is often protected by the lock crtc->dev->event_lock when is accessed. However, it is accessed as a condition of an if statement in exynos_drm_crtc_atomic_disable() without holding the lock: if (crtc->state->event && !crtc->state->active) However, if crtc->state->event is changed to NULL by another thread right after the conditions of the if statement is checked to be true, a null-pointer dereference can occur in drm_crtc_send_vblank_event(): e->pipe = pipe; To fix this possible null-pointer dereference caused by data race, the spin lock coverage is extended to protect the if statement as well as the function call to drm_crtc_send_vblank_event(). Reported-by: BassCheck <bass@buaa.edu.cn> Link: https://sites.google.com/view/basscheck/home Signed-off-by: Tuo Li <islituo@gmail.com> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Added relevant link. Signed-off-by: Inki Dae <inki.dae@samsung.com> Signed-off-by: Sasha Levin <sashal@kernel.org>