drm/radeon: fix race condition UAF in radeon_gem_set_domain_ioctl
[ Upstream commit 982b173a6c6d9472730c3116051977e05d17c8c5 ]
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 <christian.koenig@amd.com>
Signed-off-by: Min Li <lm0963hack@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/drivers/gpu/drm/radeon/radeon_gem.c b/drivers/gpu/drm/radeon/radeon_gem.c
index ac467b8..59ad0a4 100644
--- a/drivers/gpu/drm/radeon/radeon_gem.c
+++ b/drivers/gpu/drm/radeon/radeon_gem.c
@@ -376,7 +376,6 @@
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 -
@@ -389,13 +388,12 @@
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_unlocked(gobj);
up_read(&rdev->exclusive_lock);
- r = radeon_gem_handle_lockup(robj->rdev, r);
+ r = radeon_gem_handle_lockup(rdev, r);
return r;
}