From 982b173a6c6d9472730c3116051977e05d17c8c5 Mon Sep 17 00:00:00 2001 From: Min Li Date: Sat, 3 Jun 2023 15:43:45 +0800 Subject: [PATCH] drm/radeon: fix race condition UAF in radeon_gem_set_domain_ioctl MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Userspace can race to free the gobj(robj converted from), robj should not be accessed again after drm_gem_object_put, otherwith it will result in use-after-free. Reviewed-by: Christian König Signed-off-by: Min Li Signed-off-by: Alex Deucher --- drivers/gpu/drm/radeon/radeon_gem.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/gpu/drm/radeon/radeon_gem.c b/drivers/gpu/drm/radeon/radeon_gem.c index bdc5af23f005..d3f5ddbc1704 100644 --- a/drivers/gpu/drm/radeon/radeon_gem.c +++ b/drivers/gpu/drm/radeon/radeon_gem.c @@ -459,7 +459,6 @@ int radeon_gem_set_domain_ioctl(struct drm_device *dev, void *data, struct radeon_device *rdev = dev->dev_private; struct drm_radeon_gem_set_domain *args = data; struct drm_gem_object *gobj; - struct radeon_bo *robj; int r; /* for now if someone requests domain CPU - @@ -472,13 +471,12 @@ int radeon_gem_set_domain_ioctl(struct drm_device *dev, void *data, up_read(&rdev->exclusive_lock); return -ENOENT; } - robj = gem_to_radeon_bo(gobj); r = radeon_gem_set_domain(gobj, args->read_domains, args->write_domain); drm_gem_object_put(gobj); up_read(&rdev->exclusive_lock); - r = radeon_gem_handle_lockup(robj->rdev, r); + r = radeon_gem_handle_lockup(rdev, r); return r; } -- 2.20.1