diff options
Diffstat (limited to 'net/netlink/af_netlink.c')
-rw-r--r-- | net/netlink/af_netlink.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index c20c41801845..65cf129eaad3 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -574,7 +574,10 @@ static int netlink_insert(struct sock *sk, u32 portid) /* We need to ensure that the socket is hashed and visible. */ smp_wmb(); - nlk_sk(sk)->bound = portid; + /* Paired with lockless reads from netlink_bind(), + * netlink_connect() and netlink_sendmsg(). + */ + WRITE_ONCE(nlk_sk(sk)->bound, portid); err: release_sock(sk); @@ -993,7 +996,8 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr, else if (nlk->ngroups < 8*sizeof(groups)) groups &= (1UL << nlk->ngroups) - 1; - bound = nlk->bound; + /* Paired with WRITE_ONCE() in netlink_insert() */ + bound = READ_ONCE(nlk->bound); if (bound) { /* Ensure nlk->portid is up-to-date. */ smp_rmb(); @@ -1073,8 +1077,9 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr, /* No need for barriers here as we return to user-space without * using any of the bound attributes. + * Paired with WRITE_ONCE() in netlink_insert(). */ - if (!nlk->bound) + if (!READ_ONCE(nlk->bound)) err = netlink_autobind(sock); if (err == 0) { @@ -1821,7 +1826,8 @@ static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) dst_group = nlk->dst_group; } - if (!nlk->bound) { + /* Paired with WRITE_ONCE() in netlink_insert() */ + if (!READ_ONCE(nlk->bound)) { err = netlink_autobind(sock); if (err) goto out; @@ -2405,13 +2411,15 @@ int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, /* errors reported via destination sk->sk_err, but propagate * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ err = nlmsg_multicast(sk, skb, exclude_portid, group, flags); + if (err == -ESRCH) + err = 0; } if (report) { int err2; err2 = nlmsg_unicast(sk, skb, portid); - if (!err || err == -ESRCH) + if (!err) err = err2; } |