[PATCH v2] drm/nouveau/secboot: remove VLA usage

Kees Cook keescook at chromium.org
Wed May 23 22:48:12 UTC 2018

On Thu, Apr 26, 2018 at 4:25 PM, Kees Cook <keescook at chromium.org> wrote:
> On Thu, Mar 15, 2018 at 7:05 PM, Ben Skeggs <skeggsb at gmail.com> wrote:
>> On 14 March 2018 at 21:08, Thierry Reding <thierry.reding at gmail.com> wrote:
>>> On Tue, Mar 13, 2018 at 11:24:11AM -0500, Gustavo A. R. Silva wrote:
>>>> In preparation to enabling -Wvla, remove VLA. In this particular
>>>> case directly use macro NVKM_MSGQUEUE_CMDLINE_SIZE instead of local
>>>> variable cmdline_size. Also, remove cmdline_size as it is not
>>>> actually useful anymore.
>>>> The use of stack Variable Length Arrays needs to be avoided, as they
>>>> can be a vector for stack exhaustion, which can be both a runtime bug
>>>> or a security flaw. Also, in general, as code evolves it is easy to
>>>> lose track of how big a VLA can get. Thus, we can end up having runtime
>>>> failures that are hard to debug.
>>>> Also, fixed as part of the directive to remove all VLAs from
>>>> the kernel: https://lkml.org/lkml/2018/3/7/621
>>>> Signed-off-by: Gustavo A. R. Silva <gustavo at embeddedor.com>
>>>> ---
>>>> Changes in v2:
>>>>  - Use sizeof(buf) instead of NVKM_MSGQUEUE_CMDLINE_SIZE. This change
>>>>    is based on the feedback provided by David Laight. Thanks David.
>>>>  drivers/gpu/drm/nouveau/nvkm/subdev/secboot/ls_ucode_msgqueue.c | 7 +++----
>>>>  1 file changed, 3 insertions(+), 4 deletions(-)
>>> Reviewed-by: Thierry Reding <treding at nvidia.com>
>> Thanks everyone.  I've taken the patch in my tree.
> Hi!
> Just checking in on this -- I don't see this patch in linux-next. Is
> this queued somewhere else?

Hi, it's been another month; I still don't see this in linux-next.
Daniel, can this go via drm-misc?


Kees Cook
Pixel Security

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