From: Xin Long Date: Sun, 31 Mar 2019 09:03:02 +0000 (+0800) Subject: net: use rcu_dereference_protected to fetch sk_dst_cache in sk_destruct X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=5869b8fadad0be948e310c456f111c4103f5fbfb;p=linux.git net: use rcu_dereference_protected to fetch sk_dst_cache in sk_destruct As Eric noticed, in .sk_destruct, sk->sk_dst_cache update is prevented, and no barrier is needed for this. So change to use rcu_dereference_protected() instead of rcu_dereference_check() to fetch sk_dst_cache in there. v1->v2: - no change, repost after net-next is open. Reported-by: Eric Dumazet Signed-off-by: Xin Long Signed-off-by: David S. Miller --- diff --git a/net/decnet/af_decnet.c b/net/decnet/af_decnet.c index bdccc46a29219..c1fa4785c4c25 100644 --- a/net/decnet/af_decnet.c +++ b/net/decnet/af_decnet.c @@ -444,7 +444,7 @@ static void dn_destruct(struct sock *sk) skb_queue_purge(&scp->other_xmit_queue); skb_queue_purge(&scp->other_receive_queue); - dst_release(rcu_dereference_check(sk->sk_dst_cache, 1)); + dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1)); } static unsigned long dn_memory_pressure; diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 7f3a984ad6185..08a8430f5647d 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -160,7 +160,7 @@ void inet_sock_destruct(struct sock *sk) WARN_ON(sk->sk_forward_alloc); kfree(rcu_dereference_protected(inet->inet_opt, 1)); - dst_release(rcu_dereference_check(sk->sk_dst_cache, 1)); + dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1)); dst_release(sk->sk_rx_dst); sk_refcnt_debug_dec(sk); }