From 6b724bc4300b431443f3b99520994a5aece347cd Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 12 Sep 2023 16:02:11 +0000 Subject: ipv6: lockless IPV6_MTU_DISCOVER implementation Most np->pmtudisc reads are racy. Move this 3bit field on a full byte, add annotations and make IPV6_MTU_DISCOVER setsockopt() lockless. Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Signed-off-by: David S. Miller --- net/ipv6/raw.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv6/raw.c') diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c index 71f6bdccfa1f..47372cceb98f 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -307,7 +307,7 @@ static void rawv6_err(struct sock *sk, struct sk_buff *skb, harderr = icmpv6_err_convert(type, code, &err); if (type == ICMPV6_PKT_TOOBIG) { ip6_sk_update_pmtu(skb, sk, info); - harderr = (np->pmtudisc == IPV6_PMTUDISC_DO); + harderr = (READ_ONCE(np->pmtudisc) == IPV6_PMTUDISC_DO); } if (type == NDISC_REDIRECT) { ip6_sk_redirect(skb, sk); -- cgit v1.2.3