From: Herbert Xu Date: Fri, 22 Nov 2013 02:31:29 +0000 (+0800) Subject: gro: Only verify TCP checksums for candidates X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=cc5c00bbb44c5d68b883aa5cb9d01514a2525d94;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git 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 Signed-off-by: Herbert Xu Acked-by: Alexander Duyck Thanks, Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c index a2b68a108eae..55aeec930140 100644 --- a/net/ipv4/tcp_offload.c +++ b/net/ipv4/tcp_offload.c @@ -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); } diff --git a/net/ipv6/tcpv6_offload.c b/net/ipv6/tcpv6_offload.c index c1097c798900..71923d14127a 100644 --- a/net/ipv6/tcpv6_offload.c +++ b/net/ipv6/tcpv6_offload.c @@ -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); }