[lxc-devel] [PATCH] check for data in nla_put() to avoid invalid memcpy() calls

[Rafał Miłecki]

On Sun, 29 Jul 2018 at 18:39, Christian Brauner <christian at brauner.io> wrote:
> On Sun, Jul 29, 2018 at 05:44:06PM +0200, Rafał Miłecki wrote:
> > From: Rafał Miłecki <rafal at milecki.pl>
> >
> > It's a valid case to call nla_put() with NULL data and 0 len. It's done
> > e.g. in the nla_put_attr().
> >
> > There has to be a check for data in nla_put() as passing NULL to the
> > memcpy() is not allowed. Even if length is 0, both pointers have to be
> > valid.
> >
> > For a reference see C99 standard (7.21.1/2), it says: "pointer arguments
> > on such a call shall still have valid values".
> >
> > Reported-by: Daniel Gimpelevich <daniel at gimpelevich.san-francisco.ca.us>
> > Signed-off-by: Rafał Miłecki <rafal at milecki.pl>
>
> Thanks, I've created a branch at https://github.com/lxc/lxc/pull/2497 .
>
> Acked-by: Christian Brauner <christian.brauner at ubuntu.com>

Thanks!

-- 
Rafał