From 4a5e31bdd3c1702b520506d9cf8c41085f75c7f2 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 2 Feb 2024 09:54:04 +0000 Subject: [PATCH] inet: read sk->sk_family once in inet_recv_error() [ Upstream commit eef00a82c568944f113f2de738156ac591bbd5cd ] inet_recv_error() is called without holding the socket lock. IPv6 socket could mutate to IPv4 with IPV6_ADDRFORM socket option and trigger a KCSAN warning. Fixes: f4713a3dfad0 ("net-timestamp: make tcp_recvmsg call ipv6_recv_error for AF_INET6 socks") Signed-off-by: Eric Dumazet Cc: Willem de Bruijn Reviewed-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/af_inet.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 1c58bd7..e59962f 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1628,10 +1628,12 @@ EXPORT_SYMBOL(inet_current_timestamp); int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len) { - if (sk->sk_family == AF_INET) + unsigned int family = READ_ONCE(sk->sk_family); + + if (family == AF_INET) return ip_recv_error(sk, msg, len, addr_len); #if IS_ENABLED(CONFIG_IPV6) - if (sk->sk_family == AF_INET6) + if (family == AF_INET6) return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len); #endif return -EINVAL; -- 2.7.4