gro: Only verify TCP checksums for candidates

In some cases we may receive IP packets that are longer than
their stated lengths.  Such packets are never merged in GRO.
However, we may end up computing their checksums incorrectly
and end up allowing packets with a bogus checksum enter our
stack with the checksum status set as verified.

Since such packets are rare and not performance-critical, this
patch simply skips the checksum verification for them.

Reported-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>

Thanks,
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Herbert Xu 2013-11-22 10:31:29 +08:00 committed by David S. Miller
parent d6c4161485
commit cc5c00bbb4
2 changed files with 10 additions and 0 deletions

View File

@ -276,6 +276,10 @@ static struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *
__wsum wsum; __wsum wsum;
__sum16 sum; __sum16 sum;
/* Don't bother verifying checksum if we're going to flush anyway. */
if (NAPI_GRO_CB(skb)->flush)
goto skip_csum;
switch (skb->ip_summed) { switch (skb->ip_summed) {
case CHECKSUM_COMPLETE: case CHECKSUM_COMPLETE:
if (!tcp_v4_check(skb_gro_len(skb), iph->saddr, iph->daddr, if (!tcp_v4_check(skb_gro_len(skb), iph->saddr, iph->daddr,
@ -301,6 +305,7 @@ flush:
break; break;
} }
skip_csum:
return tcp_gro_receive(head, skb); return tcp_gro_receive(head, skb);
} }

View File

@ -39,6 +39,10 @@ static struct sk_buff **tcp6_gro_receive(struct sk_buff **head,
__wsum wsum; __wsum wsum;
__sum16 sum; __sum16 sum;
/* Don't bother verifying checksum if we're going to flush anyway. */
if (NAPI_GRO_CB(skb)->flush)
goto skip_csum;
switch (skb->ip_summed) { switch (skb->ip_summed) {
case CHECKSUM_COMPLETE: case CHECKSUM_COMPLETE:
if (!tcp_v6_check(skb_gro_len(skb), &iph->saddr, &iph->daddr, if (!tcp_v6_check(skb_gro_len(skb), &iph->saddr, &iph->daddr,
@ -65,6 +69,7 @@ flush:
break; break;
} }
skip_csum:
return tcp_gro_receive(head, skb); return tcp_gro_receive(head, skb);
} }