diff options
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 20 | ||||
| -rw-r--r-- | net/ipv6/tcp_ipv6.c | 15 |
2 files changed, 25 insertions, 10 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 3f9bc3f..7881b96 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1559,7 +1559,17 @@ bool tcp_prequeue(struct sock *sk, struct sk_buff *skb) skb_queue_len(&tp->ucopy.prequeue) == 0) return false; - skb_dst_force(skb); + /* Before escaping RCU protected region, we need to take care of skb + * dst. Prequeue is only enabled for established sockets. + * For such sockets, we might need the skb dst only to set sk->sk_rx_dst + * Instead of doing full sk_rx_dst validity here, let's perform + * an optimistic check. + */ + if (likely(sk->sk_rx_dst)) + skb_dst_drop(skb); + else + skb_dst_force(skb); + __skb_queue_tail(&tp->ucopy.prequeue, skb); tp->ucopy.memory += skb->truesize; if (tp->ucopy.memory > sk->sk_rcvbuf) { @@ -1765,9 +1775,11 @@ void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb) { struct dst_entry *dst = skb_dst(skb); - dst_hold(dst); - sk->sk_rx_dst = dst; - inet_sk(sk)->rx_dst_ifindex = skb->skb_iif; + if (dst) { + dst_hold(dst); + sk->sk_rx_dst = dst; + inet_sk(sk)->rx_dst_ifindex = skb->skb_iif; + } } EXPORT_SYMBOL(inet_sk_rx_dst_set); diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 5b3c70f..1835480 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -93,13 +93,16 @@ static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk, static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb) { struct dst_entry *dst = skb_dst(skb); - const struct rt6_info *rt = (const struct rt6_info *)dst; - dst_hold(dst); - sk->sk_rx_dst = dst; - inet_sk(sk)->rx_dst_ifindex = skb->skb_iif; - if (rt->rt6i_node) - inet6_sk(sk)->rx_dst_cookie = rt->rt6i_node->fn_sernum; + if (dst) { + const struct rt6_info *rt = (const struct rt6_info *)dst; + + dst_hold(dst); + sk->sk_rx_dst = dst; + inet_sk(sk)->rx_dst_ifindex = skb->skb_iif; + if (rt->rt6i_node) + inet6_sk(sk)->rx_dst_cookie = rt->rt6i_node->fn_sernum; + } } static void tcp_v6_hash(struct sock *sk) |