On Fri, 2004-06-25 at 23:57, Herbert Xu wrote:
> On Fri, Jun 25, 2004 at 10:12:31AM -0700, David S. Miller wrote:
> > I now think it's trying to account for the udpdata32 header area.
> > But that's not 2 bytes, it's (2 * sizeof(u32)) or 8 bytes.
> That's what I thought too, but that is already accounted by
> x->props.header_len in init_state.
> In any case, just increasing alen like that is wrong. It needs to
> do at least three other things:
> 1. Allocate memory for it in skb_cow_data.
> 2. Fill in those bytes with data so we don't leak information.
> 3. Teach get_max_size about it.
> Andreas, can you please clarify for us as to what those two bytes
> are for?
Your analyses are entirely correct. The two instances of ``alen += 2''
are indeed complete nonsense. The extra 8 bytes required are already
accounted for in header_len; nothing other than the two zero-filled
words is required for this encapsulation mode.
Attached is a new version of the original patch, and a relative diff for
reference. Thanks for reviewing and for reporting. (And sorry for the
confusion; I'm a bit stressed out at the moment.)
Andreas Gruenbacher <agruen@xxxxxxx>
SUSE Labs, SUSE LINUX AG
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