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.stricted.de/?p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git;a=commitdiff_plain;h=8ec6068428a33e224bf9309c6130d9ec9535bf6a gro: Disable frag0 optimization on IPv6 ext headers commit 57ea52a865144aedbcd619ee0081155e658b6f7d upstream. 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 Signed-off-by: Willy Tarreau --- diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 45a618b58864..157a47c998e5 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1729,14 +1729,19 @@ 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 71b766ee821d..88a2e8827ef7 100644 --- a/net/ipv6/ip6_offload.c +++ b/net/ipv6/ip6_offload.c @@ -174,6 +174,7 @@ 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);