Re: [PATCH 2.6 NET] Catch wrong RTATTR_MAX with BUG()

["David S. Miller" <davem@xxxxxxxxxxxxx>]

On Thu, 9 Sep 2004 18:43:46 +0200
Thomas Graf <tgraf@xxxxxxx> wrote:

> Catches outdated/invalid RTATTR_MAX and therefore avoids possible stack
> corruption.

Your test has an off by one error, but more importantly,
it's probably better to do this at compile time with
something like:

extern void rtattr_max_too_small(void);

...

void __init rtnetlink_init(void)
{
        if (IFLA_MAX > RTATTR_MAX ||
            IFA_MAX > RTATTR_MAX ||
            RTA_MAX > RTATTR_MAX ||
            NDA_MAX > RTATTR_MAX ||
            TCA_MAX > RTATTR_MAX ||
            TCAA_MAX > RTATTR_MAX)
                rtattr_max_too_small();

I would therefore accept a patch that did things
this way.  BUG()'ing at runtime for something like
this is too rude. :)

Thanks.