From 87324a50b4e833289bbe22339eccbc42e4d0578a Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 21 Sep 2023 20:28:18 +0000 Subject: [PATCH] net: annotate data-races around sk->sk_dst_pending_confirm [ Upstream commit eb44ad4e635132754bfbcb18103f1dcb7058aedd ] This field can be read or written without socket lock being held. Add annotations to avoid load-store tearing. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- include/net/sock.h | 6 +++--- net/core/sock.c | 2 +- net/ipv4/tcp_output.c | 2 +- 3 files changed, 5 insertions(+), 5 deletions(-) diff --git a/include/net/sock.h b/include/net/sock.h index 97f7fbc..7753354 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2181,7 +2181,7 @@ static inline void __dst_negative_advice(struct sock *sk) if (ndst != dst) { rcu_assign_pointer(sk->sk_dst_cache, ndst); sk_tx_queue_clear(sk); - sk->sk_dst_pending_confirm = 0; + WRITE_ONCE(sk->sk_dst_pending_confirm, 0); } } } @@ -2198,7 +2198,7 @@ __sk_dst_set(struct sock *sk, struct dst_entry *dst) struct dst_entry *old_dst; sk_tx_queue_clear(sk); - sk->sk_dst_pending_confirm = 0; + WRITE_ONCE(sk->sk_dst_pending_confirm, 0); old_dst = rcu_dereference_protected(sk->sk_dst_cache, lockdep_sock_is_held(sk)); rcu_assign_pointer(sk->sk_dst_cache, dst); @@ -2211,7 +2211,7 @@ sk_dst_set(struct sock *sk, struct dst_entry *dst) struct dst_entry *old_dst; sk_tx_queue_clear(sk); - sk->sk_dst_pending_confirm = 0; + WRITE_ONCE(sk->sk_dst_pending_confirm, 0); old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst); dst_release(old_dst); } diff --git a/net/core/sock.c b/net/core/sock.c index 16584e2..bfaf47b 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -600,7 +600,7 @@ struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie) INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check, ipv4_dst_check, dst, cookie) == NULL) { sk_tx_queue_clear(sk); - sk->sk_dst_pending_confirm = 0; + WRITE_ONCE(sk->sk_dst_pending_confirm, 0); RCU_INIT_POINTER(sk->sk_dst_cache, NULL); dst_release(dst); return NULL; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index f0723460..9ccfdc8 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1331,7 +1331,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, skb->destructor = skb_is_tcp_pure_ack(skb) ? __sock_wfree : tcp_wfree; refcount_add(skb->truesize, &sk->sk_wmem_alloc); - skb_set_dst_pending_confirm(skb, sk->sk_dst_pending_confirm); + skb_set_dst_pending_confirm(skb, READ_ONCE(sk->sk_dst_pending_confirm)); /* Build TCP header and checksum it. */ th = (struct tcphdr *)skb->data; -- 2.7.4