From a7386602a2fe2f6192477e8ede291a815da09d81 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Wed, 13 Jul 2022 13:51:58 -0700 Subject: [PATCH] tcp/dccp: Fix a data-race around sysctl_tcp_fwmark_accept. [ Upstream commit 1a0008f9df59451d0a17806c1ee1a19857032fa8 ] While reading sysctl_tcp_fwmark_accept, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 84f39b08d786 ("net: support marking accepting TCP sockets") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- include/net/inet_sock.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h index 40f92f5a3047..58db7c69c146 100644 --- a/include/net/inet_sock.h +++ b/include/net/inet_sock.h @@ -107,7 +107,8 @@ static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk) static inline u32 inet_request_mark(const struct sock *sk, struct sk_buff *skb) { - if (!sk->sk_mark && sock_net(sk)->ipv4.sysctl_tcp_fwmark_accept) + if (!sk->sk_mark && + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fwmark_accept)) return skb->mark; return sk->sk_mark;