Re: [PATCH v2] rtc: remove VLA usage

From: Alexandre Belloni
Date: Thu Mar 08 2018 - 04:52:45 EST


On 07/03/2018 at 20:27:56 -0600, Gustavo A. R. Silva wrote:
> In preparation to enabling -Wvla, remove VLA and replace it
> with a fixed-length array instead.
>
> From a security viewpoint, the use of Variable Length Arrays can be
> a vector for stack overflow attacks. Also, in general, as the code
> evolves it is easy to lose track of how big a VLA can get. Thus, we
> can end up having segfaults 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
>

That is a good description, thanks

> Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
> ---
> Changes in v2:
> - Update changelog as per Alexandre Belloni request.
> - Update the code for rtc-bq32k driver based on Alexandre's feedback.
>
> drivers/rtc/rtc-bq32k.c | 6 +++++-
> drivers/rtc/rtc-mcp795.c | 2 +-
> 2 files changed, 6 insertions(+), 2 deletions(-)
>
Applied.

--
Alexandre Belloni, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com