Re: [PATCH] rtnetlink: Remove VLA usage

From: David Miller
Date: Thu May 31 2018 - 22:49:46 EST


From: Kees Cook <keescook@xxxxxxxxxxxx>
Date: Wed, 30 May 2018 15:20:52 -0700

> In the quest to remove all stack VLA usage from the kernel[1], this
> allocates the maximum size expected for all possible types and adds
> sanity-checks at both registration and usage to make sure nothing gets
> out of sync. This matches the proposed VLA solution for nfnetlink[2]. The
> values chosen here were based on finding assignments for .maxtype and
> .slave_maxtype and manually counting the enums:
>
> slave_maxtype (max 33):
...
> maxtype (max 45):
...
>
> This additionally changes maxtype and slave_maxtype fields to unsigned,
> since they're only ever using positive values.
>
> [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@xxxxxxxxxxxxxx
> [2] https://patchwork.kernel.org/patch/10439647/
>
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

Looks good, applied, thanks.