gro: Only verify TCP checksums for candidates (cc5c00bb) · Commits · 戴 / test

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>

net/ipv4/tcp_offload.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -276,6 +276,10 @@ static struct sk_buff tcp4_gro_receive(struct sk_buff head, struct sk_buff *
		__wsum wsum;
		__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) {
		case CHECKSUM_COMPLETE:
		if (!tcp_v4_check(skb_gro_len(skb), iph->saddr, iph->daddr,
		@@ -301,6 +305,7 @@ flush:
		break;
		}

		skip_csum:
		return tcp_gro_receive(head, skb);
		}

net/ipv6/tcpv6_offload.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -39,6 +39,10 @@ static struct sk_buff tcp6_gro_receive(struct sk_buff head,
		__wsum wsum;
		__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) {
		case CHECKSUM_COMPLETE:
		if (!tcp_v6_check(skb_gro_len(skb), &iph->saddr, &iph->daddr,
		@@ -65,6 +69,7 @@ flush:
		break;
		}

		skip_csum:
		return tcp_gro_receive(head, skb);
		}

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