Re: [PATCH] fortify: Provide a memcpy trap door for sharp corners

From: Jakub Kicinski
Date: Wed May 11 2022 - 12:24:23 EST


On Tue, 10 May 2022 19:53:01 -0700 Kees Cook wrote:
> As we continue to narrow the scope of what the FORTIFY memcpy() will
> accept and build alternative APIs that give the compiler appropriate
> visibility into more complex memcpy scenarios, there is a need for
> "unfortified" memcpy use in rare cases where combinations of compiler
> behaviors, source code layout, etc, result in cases where the stricter
> memcpy checks need to be bypassed until appropriate solutions can be
> developed (i.e. fix compiler bugs, code refactoring, new API, etc). The
> intention is for this to be used only if there's no other reasonable
> solution, for its use to include a justification that can be used
> to assess future solutions, and for it to be temporary.
>
> Example usage included, based on analysis and discussion from:
> https://lore.kernel.org/netdev/CANn89iLS_2cshtuXPyNUGDPaic=sJiYfvTb_wNLgWrZRyBxZ_g@xxxxxxxxxxxxxx

Saeed, ack for taking this in directly? Or do you prefer to take this
plus Eric's last BIG TCP patch via your tree?