From 7124882caac17b1d5de7eed9faf2ad5cfd2f07aa Mon Sep 17 00:00:00 2001 From: Emil Velikov Date: Sun, 21 Aug 2011 22:41:28 +0100 Subject: [PATCH] drm/nv50/crtc: Bail out if FB is not bound to crtc Fixes possbile NULL pointer dereference Resolves 'kernel crash in nv50_crtc_do_mode_set_base during shutdown' https://bugs.freedesktop.org/show_bug.cgi?id=40005 Signed-off-by: Emil Velikov --- drivers/gpu/drm/nouveau/nv50_crtc.c | 12 ++++++++++-- 1 files changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nv50_crtc.c b/drivers/gpu/drm/nouveau/nv50_crtc.c index 636e3fb..882080e 100644 --- a/drivers/gpu/drm/nouveau/nv50_crtc.c +++ b/drivers/gpu/drm/nouveau/nv50_crtc.c @@ -517,12 +517,18 @@ nv50_crtc_do_mode_set_base(struct drm_crtc *crtc, struct drm_device *dev = nv_crtc->base.dev; struct drm_nouveau_private *dev_priv = dev->dev_private; struct nouveau_channel *evo = nv50_display(dev)->master; - struct drm_framebuffer *drm_fb = nv_crtc->base.fb; - struct nouveau_framebuffer *fb = nouveau_framebuffer(drm_fb); + struct drm_framebuffer *drm_fb; + struct nouveau_framebuffer *fb; int ret; NV_DEBUG_KMS(dev, "index %d\n", nv_crtc->index); + /* no fb bound */ + if (!atomic && !crtc->fb) { + NV_DEBUG_KMS(dev, "No FB bound\n"); + return 0; + } + /* If atomic, we want to switch to the fb we were passed, so * now we update pointers to do that. (We don't pin; just * assume we're already pinned and update the base address.) @@ -531,6 +537,8 @@ nv50_crtc_do_mode_set_base(struct drm_crtc *crtc, drm_fb = passed_fb; fb = nouveau_framebuffer(passed_fb); } else { + drm_fb = crtc->fb; + fb = nouveau_framebuffer(crtc->fb); /* If not atomic, we can go ahead and pin, and unpin the * old fb we were passed. */ -- 1.7.6