From 0d1430a3f4b7cfd8779b78740a4182321f3ca7f3 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 4 Dec 2013 14:52:06 +0000 Subject: [PATCH] drm/i915: Hold mutex across i915_gem_release Inorder to serialise the closing of the file descriptor and its subsequent release of client requests with i915_gem_free_request(), we need to hold the struct_mutex in i915_gem_release(). Failing to do so has the potential to trigger an OOPS, later with a use-after-free. Testcase: igt/gem_close_race Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=70874 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=71029 Reported-by: Eric Anholt Signed-off-by: Chris Wilson Cc: stable@vger.kernel.org Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_dma.c | 2 ++ drivers/gpu/drm/i915/i915_gem_context.c | 2 -- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c index 0cab2d045135..ac9dac99b585 100644 --- a/drivers/gpu/drm/i915/i915_dma.c +++ b/drivers/gpu/drm/i915/i915_dma.c @@ -1848,8 +1848,10 @@ void i915_driver_lastclose(struct drm_device * dev) void i915_driver_preclose(struct drm_device * dev, struct drm_file *file_priv) { + mutex_lock(&dev->struct_mutex); i915_gem_context_close(dev, file_priv); i915_gem_release(dev, file_priv); + mutex_unlock(&dev->struct_mutex); } void i915_driver_postclose(struct drm_device *dev, struct drm_file *file) diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c index 72a3df32292f..4a05956162c1 100644 --- a/drivers/gpu/drm/i915/i915_gem_context.c +++ b/drivers/gpu/drm/i915/i915_gem_context.c @@ -347,10 +347,8 @@ void i915_gem_context_close(struct drm_device *dev, struct drm_file *file) { struct drm_i915_file_private *file_priv = file->driver_priv; - mutex_lock(&dev->struct_mutex); idr_for_each(&file_priv->context_idr, context_idr_cleanup, NULL); idr_destroy(&file_priv->context_idr); - mutex_unlock(&dev->struct_mutex); } static struct i915_hw_context * -- 2.20.1