From: Herbert Xu <[EMAIL PROTECTED]> Date: Sun, 21 Oct 2007 12:56:01 +0800
> [NET]: Fix SKB_WITH_OVERHEAD calculation > > The calculation in SKB_WITH_OVERHEAD is incorrect in that it can cause > an overflow across a page boundary which is what it's meant to prevent. > In particular, the header length (X) should not be lumped together with > skb_shared_info. The latter needs to be aligned properly while the header > has no choice but to sit in front of wherever the payload is. > > Therefore the correct calculation is to take away the aligned size of > skb_shared_info, and then subtract the header length. The resulting > quantity L satisfies the following inequality: > > SKB_DATA_ALIGN(L + X) + sizeof(struct skb_shared_info) <= PAGE_SIZE > > This is the quantity used by alloc_skb to do the actual allocation. > > Signed-off-by: Herbert Xu <[EMAIL PROTECTED]> Applied, I'll push this to -stable too, thanks! - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
