From 4a5e31bdd3c1702b520506d9cf8c41085f75c7f2 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
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 <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 1c58bd72e124..e59962f34caa 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;