Re: [PATCH 2/2] exec: increase BINPRM_BUF_SIZE to 256

From: Oleg Nesterov
Date: Wed Nov 14 2018 - 10:54:19 EST


On 11/13, Andrew Morton wrote:
>
> On Tue, 13 Nov 2018 17:55:58 +0100 Oleg Nesterov <oleg@xxxxxxxxxx> wrote:
>
> > > However it would be basically cost-free to increase
> > > BINPRM_BUF_SIZE up to the point where sizeof(struct linux_binprm) ==
> > > PAGE_SIZE?
> >
> > I don't think we should take sizeof(struct linux_binprm) into account, the
> > new members can come at any time and we can never decrease BINPRM_BUF_SIZE.
>
> My main point is.. why not make BINPRM_BUF_SIZE a lot larger than 256?

Of course we can make it larger. And of course 256 is just another silly/random
value. Currently it seems to work, but if we have another bug report we should
probably rework load_script() to use vmalloc()'ed buffer. Perhaps we should do
this right now and I am just too lazy.

Oleg.