From 2368ffb18b1d2b04eb80478d225676caa7a3c4c8 Mon Sep 17 00:00:00 2001 From: Mario Kleiner Date: Wed, 6 Aug 2014 03:22:46 +0200 Subject: [PATCH] drm: Use vblank_disable_and_save in drm_vblank_cleanup() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Calling vblank_disable_fn() will cause that function to no-op if !dev->vblank_disable_allowed for some kms drivers, e.g., on nouveau-kms. This can cause the gpu vblank irq's to not get disabled before freeing the dev->vblank array, so if a vblank irq fires and calls into drm_handle_vblank() after drm_vblank_cleanup() completes, it will cause use-after-free access to dev->vblank array. Call vblank_disable_and_save unconditionally, so vblank irqs are guaranteed to be off, before we delete the data structures on which they operate. Signed-off-by: Mario Kleiner Reviewed-by: Ville Syrjälä [danvet: Fix subsystem name in patch subject.] Signed-off-by: Daniel Vetter --- drivers/gpu/drm/drm_irq.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 6473089e5fd3..9be760145cb7 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -239,6 +239,7 @@ static void vblank_disable_fn(unsigned long arg) void drm_vblank_cleanup(struct drm_device *dev) { int crtc; + unsigned long irqflags; /* Bail if the driver didn't call drm_vblank_init() */ if (dev->num_crtcs == 0) @@ -248,7 +249,10 @@ void drm_vblank_cleanup(struct drm_device *dev) struct drm_vblank_crtc *vblank = &dev->vblank[crtc]; del_timer_sync(&vblank->disable_timer); - vblank_disable_fn((unsigned long)vblank); + + spin_lock_irqsave(&dev->vbl_lock, irqflags); + vblank_disable_and_save(dev, crtc); + spin_unlock_irqrestore(&dev->vbl_lock, irqflags); } kfree(dev->vblank); -- 2.20.1