ip: Fix data-races around sysctl_ip_nonlocal_bind.

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>

diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index daead5f..68d3377 100644 (file)
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -374,7 +374,7 @@ 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 35928fe..1a094b0 100644 (file)
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -358,7 +358,7 @@ 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)))