From: Alexey Kodanev Date: Thu, 15 Feb 2018 17:18:43 +0000 (+0300) Subject: udplite: fix partial checksum initialization X-Git-Tag: v4.1.51~55 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=3311f45c5fe1e87d4a3e5fa47509fb9e042235eb;p=platform%2Fkernel%2Flinux-exynos.git udplite: fix partial checksum initialization [ Upstream commit 15f35d49c93f4fa9875235e7bf3e3783d2dd7a1b ] Since UDP-Lite is always using checksum, the following path is triggered when calculating pseudo header for it: udp4_csum_init() or udp6_csum_init() skb_checksum_init_zero_check() __skb_checksum_validate_complete() The problem can appear if skb->len is less than CHECKSUM_BREAK. In this particular case __skb_checksum_validate_complete() also invokes __skb_checksum_complete(skb). If UDP-Lite is using partial checksum that covers only part of a packet, the function will return bad checksum and the packet will be dropped. It can be fixed if we skip skb_checksum_init_zero_check() and only set the required pseudo header checksum for UDP-Lite with partial checksum before udp4_csum_init()/udp6_csum_init() functions return. Fixes: ed70fcfcee95 ("net: Call skb_checksum_init in IPv4") Fixes: e4f45b7f40bd ("net: Call skb_checksum_init in IPv6") Signed-off-by: Alexey Kodanev Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- diff --git a/include/net/udplite.h b/include/net/udplite.h index 80761938b9a7..8228155b305e 100644 --- a/include/net/udplite.h +++ b/include/net/udplite.h @@ -62,6 +62,7 @@ static inline int udplite_checksum_init(struct sk_buff *skb, struct udphdr *uh) UDP_SKB_CB(skb)->cscov = cscov; if (skb->ip_summed == CHECKSUM_COMPLETE) skb->ip_summed = CHECKSUM_NONE; + skb->csum_valid = 0; } return 0; diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 456718921552..75758e3d6c81 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1733,6 +1733,11 @@ static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, err = udplite_checksum_init(skb, uh); if (err) return err; + + if (UDP_SKB_CB(skb)->partial_cov) { + skb->csum = inet_compute_pseudo(skb, proto); + return 0; + } } return skb_checksum_init_zero_check(skb, proto, uh->check, diff --git a/net/ipv6/ip6_checksum.c b/net/ipv6/ip6_checksum.c index 9a4d7322fb22..391a8fedb27e 100644 --- a/net/ipv6/ip6_checksum.c +++ b/net/ipv6/ip6_checksum.c @@ -73,6 +73,11 @@ int udp6_csum_init(struct sk_buff *skb, struct udphdr *uh, int proto) err = udplite_checksum_init(skb, uh); if (err) return err; + + if (UDP_SKB_CB(skb)->partial_cov) { + skb->csum = ip6_compute_pseudo(skb, proto); + return 0; + } } /* To support RFC 6936 (allow zero checksum in UDP/IPV6 for tunnels)