| Message ID | 20090604112201.GA28820@gondor.apana.org.au |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Thu, 4 Jun 2009 08:52:01 pm Herbert Xu wrote: > On Thu, Jun 04, 2009 at 09:06:00PM +1000, Herbert Xu wrote: > > tun: Optimise handling of bogus gso->hdr_len > > > > As all current versions of virtio_net generate a value for the > > header length that's too small, we should optimise this so that > > we don't copy it twice. This can be done by ensuring that it is > > at least as large as the place where we'll write the checksum. > > > > Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> > > With this applied we can strengthen the partial checksum check: > > net: Ensure partial checksum offset is inside the skb head > > In skb_partial_csum_set we check to see if the checksum offset > is within the packet. However, we really should check that it > is within the skb head as that's the only bit we can modify > without copying. > > Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Yep, makes sense. FWIW: Acked-by: Rusty Russell <rusty@rustcorp.com.au> Thanks! Rusty. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Herbert Xu <herbert@gondor.apana.org.au> Date: Thu, 4 Jun 2009 21:22:01 +1000 > On Thu, Jun 04, 2009 at 09:06:00PM +1000, Herbert Xu wrote: >> >> tun: Optimise handling of bogus gso->hdr_len >> >> As all current versions of virtio_net generate a value for the >> header length that's too small, we should optimise this so that >> we don't copy it twice. This can be done by ensuring that it is >> at least as large as the place where we'll write the checksum. >> >> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> > > With this applied we can strengthen the partial checksum check: > > net: Ensure partial checksum offset is inside the skb head > > In skb_partial_csum_set we check to see if the checksum offset > is within the packet. However, we really should check that it > is within the skb head as that's the only bit we can modify > without copying. > > Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index e505b53..643c03d 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3016,12 +3016,12 @@ EXPORT_SYMBOL_GPL(skb_tstamp_tx); */ bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off) { - if (unlikely(start > skb->len - 2) || - unlikely((int)start + off > skb->len - 2)) { + if (unlikely(start > skb_headlen(skb)) || + unlikely((int)start + off > skb_headlen(skb) - 2)) { if (net_ratelimit()) printk(KERN_WARNING "bad partial csum: csum=%u/%u len=%u\n", - start, off, skb->len); + start, off, skb_headlen(skb)); return false; } skb->ip_summed = CHECKSUM_PARTIAL;