From: Herbert Xu Date: Tue, 10 Jan 2017 20:24:15 +0000 (-0800) Subject: gro: Disable frag0 optimization on IPv6 ext headers X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=57ea52a865144aedbcd619ee0081155e658b6f7d;p=linux-beck.git gro: Disable frag0 optimization on IPv6 ext headers The GRO fast path caches the frag0 address. This address becomes invalid if frag0 is modified by pskb_may_pull or its variants. So whenever that happens we must disable the frag0 optimization. This is usually done through the combination of gro_header_hard and gro_header_slow, however, the IPv6 extension header path did the pulling directly and would continue to use the GRO fast path incorrectly. This patch fixes it by disabling the fast path when we enter the IPv6 extension header path. Fixes: 78a478d0efd9 ("gro: Inline skb_gro_header and cache frag0 virtual address") Reported-by: Slava Shwartsman Signed-off-by: Herbert Xu Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 994f7423a74b..9bde9558b596 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2477,14 +2477,19 @@ static inline int skb_gro_header_hard(struct sk_buff *skb, unsigned int hlen) return NAPI_GRO_CB(skb)->frag0_len < hlen; } +static inline void skb_gro_frag0_invalidate(struct sk_buff *skb) +{ + NAPI_GRO_CB(skb)->frag0 = NULL; + NAPI_GRO_CB(skb)->frag0_len = 0; +} + static inline void *skb_gro_header_slow(struct sk_buff *skb, unsigned int hlen, unsigned int offset) { if (!pskb_may_pull(skb, hlen)) return NULL; - NAPI_GRO_CB(skb)->frag0 = NULL; - NAPI_GRO_CB(skb)->frag0_len = 0; + skb_gro_frag0_invalidate(skb); return skb->data + offset; } diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c index 89c59e656f44..fc7b4017ba24 100644 --- a/net/ipv6/ip6_offload.c +++ b/net/ipv6/ip6_offload.c @@ -191,6 +191,7 @@ static struct sk_buff **ipv6_gro_receive(struct sk_buff **head, ops = rcu_dereference(inet6_offloads[proto]); if (!ops || !ops->callbacks.gro_receive) { __pskb_pull(skb, skb_gro_offset(skb)); + skb_gro_frag0_invalidate(skb); proto = ipv6_gso_pull_exthdrs(skb, proto); skb_gro_pull(skb, -skb_transport_offset(skb)); skb_reset_transport_header(skb);