From d188ba86dd07a72ebebfa22fe9cb0b0572e57740 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 8 Dec 2015 07:22:02 -0800 Subject: xfrm: add rcu protection to sk->sk_policy[] XFRM can deal with SYNACK messages, sent while listener socket is not locked. We add proper rcu protection to __xfrm_sk_clone_policy() and xfrm_sk_policy_lookup() This might serve as the first step to remove xfrm.xfrm_policy_lock use in fast path. Fixes: fa76ce7328b2 ("inet: get rid of central tcp/dccp listener timer") Signed-off-by: Eric Dumazet Acked-by: Steffen Klassert Signed-off-by: David S. Miller --- include/net/sock.h | 2 +- include/net/xfrm.h | 24 +++++++++++++++--------- 2 files changed, 16 insertions(+), 10 deletions(-) (limited to 'include') diff --git a/include/net/sock.h b/include/net/sock.h index b1d475b5db68..eaef41433d7a 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -388,7 +388,7 @@ struct sock { struct socket_wq *sk_wq_raw; }; #ifdef CONFIG_XFRM - struct xfrm_policy *sk_policy[2]; + struct xfrm_policy __rcu *sk_policy[2]; #endif struct dst_entry *sk_rx_dst; struct dst_entry __rcu *sk_dst_cache; diff --git a/include/net/xfrm.h b/include/net/xfrm.h index 8bae1ef647cd..d6f6e5006ee9 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -1142,12 +1142,14 @@ static inline int xfrm6_route_forward(struct sk_buff *skb) return xfrm_route_forward(skb, AF_INET6); } -int __xfrm_sk_clone_policy(struct sock *sk); +int __xfrm_sk_clone_policy(struct sock *sk, const struct sock *osk); -static inline int xfrm_sk_clone_policy(struct sock *sk) +static inline int xfrm_sk_clone_policy(struct sock *sk, const struct sock *osk) { - if (unlikely(sk->sk_policy[0] || sk->sk_policy[1])) - return __xfrm_sk_clone_policy(sk); + sk->sk_policy[0] = NULL; + sk->sk_policy[1] = NULL; + if (unlikely(osk->sk_policy[0] || osk->sk_policy[1])) + return __xfrm_sk_clone_policy(sk, osk); return 0; } @@ -1155,12 +1157,16 @@ int xfrm_policy_delete(struct xfrm_policy *pol, int dir); static inline void xfrm_sk_free_policy(struct sock *sk) { - if (unlikely(sk->sk_policy[0] != NULL)) { - xfrm_policy_delete(sk->sk_policy[0], XFRM_POLICY_MAX); + struct xfrm_policy *pol; + + pol = rcu_dereference_protected(sk->sk_policy[0], 1); + if (unlikely(pol != NULL)) { + xfrm_policy_delete(pol, XFRM_POLICY_MAX); sk->sk_policy[0] = NULL; } - if (unlikely(sk->sk_policy[1] != NULL)) { - xfrm_policy_delete(sk->sk_policy[1], XFRM_POLICY_MAX+1); + pol = rcu_dereference_protected(sk->sk_policy[1], 1); + if (unlikely(pol != NULL)) { + xfrm_policy_delete(pol, XFRM_POLICY_MAX+1); sk->sk_policy[1] = NULL; } } @@ -1170,7 +1176,7 @@ void xfrm_garbage_collect(struct net *net); #else static inline void xfrm_sk_free_policy(struct sock *sk) {} -static inline int xfrm_sk_clone_policy(struct sock *sk) { return 0; } +static inline int xfrm_sk_clone_policy(struct sock *sk, const struct sock *osk) { return 0; } static inline int xfrm6_route_forward(struct sk_buff *skb) { return 1; } static inline int xfrm4_route_forward(struct sk_buff *skb) { return 1; } static inline int xfrm6_policy_check(struct sock *sk, int dir, struct sk_buff *skb) -- cgit v1.2.3