Re: [PATCH 2/2] tbf scheduler: TSO support (update 2)

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, May 15, 2007 at 08:41:48PM +0900, Hirokazu Takahashi wrote:
>  
> @@ -924,7 +926,9 @@ cbq_dequeue_prio(struct Qdisc *sch, int 
>  				cl->xstats.borrows += skb->len;
>  #endif
>  			}
> -			q->tx_len = skb->len;
> +			q->tx_segs = skb_shinfo(skb)->gso_segs ? :
> +			  skb_shinfo(skb)->gso_size ? skb->len/skb_shinfo(skb)->gso_size + 1 : 1;
> +			q->tx_len = (skb->len - 1)/q->tx_segs + 1;

This isn't safe for Xen (and potentially other virtualisation
environments) since qdisc code runs before dev_hard_start_xmit
which is where we verify the sanity of gso_segs.  So you could
be using some arbitrary value from an untrusted source.

If you really want to use it, you should test for SKB_GSO_DODGY
on the packet which will be set if gso_segs can't be trusted.

Cheers,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
-
To unsubscribe from this list: send the line "unsubscribe linux-net" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Netdev]     [Ethernet Bridging]     [Linux 802.1Q VLAN]     [Linux Wireless]     [Kernel Newbies]     [Security]     [Linux for Hams]     [Netfilter]     [Git]     [Bugtraq]     [Yosemite News and Information]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux PCI]     [Linux Admin]     [Samba]

  Powered by Linux