drm/nouveau: avoid a use-after-free when BO init fails

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: drm/nouveau: avoid a use-after-free when BO init fails nouveau_bo_init() is backed by ttm_bo_init() and ferries its return code back to the caller. On failures, ttm_bo_init() invokes the provided destructor which should de-initialize and free the memory. Thus, when nouveau_bo_init() returns an error the gem object has already been released and the memory freed by nouveau_bo_del_ttm().

References

• https://git.kernel.org/stable/c/f86e19d918a85492ad1a01fcdc0ad5ecbdac6f96
• https://git.kernel.org/stable/c/548f2ff8ea5e0ce767ae3418d1ec5308990be87d
• https://git.kernel.org/stable/c/bcf34aa5082ee2343574bc3f4d1c126030913e54