ip: Fix data-races around sysctl_ip_nonlocal_bind.

[ Upstream commit 289d3b21fb0bfc94c4e98f10635bba1824e5f83c ]

While reading sysctl_ip_nonlocal_bind, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index a80fd0ac4563283246f4f53cea1ac0cd17b41dab..e3d943813ff8b6443e815508d686862cf7e83ef1 100644 (file)
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -357,7 +357,7 @@ static inline bool inet_get_convert_csum(struct sock *sk)
 static inline bool inet_can_nonlocal_bind(struct net *net,
                                          struct inet_sock *inet)
 {
-       return net->ipv4.sysctl_ip_nonlocal_bind ||
+       return READ_ONCE(net->ipv4.sysctl_ip_nonlocal_bind) ||
                inet->freebind || inet->transparent;
 }
 

diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 7207a9769f1a9065e7c6fc09f0ca8c1e4b02fb56..8db8209c5b617fd0ba5d777ff84ec9121ea5fcb0 100644 (file)
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -373,7 +373,7 @@ static int sctp_v4_available(union sctp_addr *addr, struct sctp_sock *sp)
        if (addr->v4.sin_addr.s_addr != htonl(INADDR_ANY) &&
           ret != RTN_LOCAL &&
           !sp->inet.freebind &&
-          !net->ipv4.sysctl_ip_nonlocal_bind)
+           !READ_ONCE(net->ipv4.sysctl_ip_nonlocal_bind))
                return 0;
 
        if (ipv6_only_sock(sctp_opt2sk(sp)))