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authorEric Dumazet <edumazet@google.com>2023-01-20 12:59:55 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-02-01 08:27:27 +0100
commitead06e3449f222037722df08da8257ebba4d69c9 (patch)
tree9b675240dbd74e2b045405eade8b464e963b2f7c /net/netlink
parentc4eb423c6b9bded9aae6aeb19960bff67cb464ff (diff)
netlink: annotate data races around sk_state
[ Upstream commit 9b663b5cbb15b494ef132a3c937641c90646eb73 ] netlink_getsockbyportid() reads sk_state while a concurrent netlink_connect() can change its value. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/netlink')
-rw-r--r--net/netlink/af_netlink.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index e041d2df9280..011ec7d9a719 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1089,7 +1089,8 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr,
return -EINVAL;
if (addr->sa_family == AF_UNSPEC) {
- sk->sk_state = NETLINK_UNCONNECTED;
+ /* paired with READ_ONCE() in netlink_getsockbyportid() */
+ WRITE_ONCE(sk->sk_state, NETLINK_UNCONNECTED);
/* dst_portid and dst_group can be read locklessly */
WRITE_ONCE(nlk->dst_portid, 0);
WRITE_ONCE(nlk->dst_group, 0);
@@ -1113,7 +1114,8 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr,
err = netlink_autobind(sock);
if (err == 0) {
- sk->sk_state = NETLINK_CONNECTED;
+ /* paired with READ_ONCE() in netlink_getsockbyportid() */
+ WRITE_ONCE(sk->sk_state, NETLINK_CONNECTED);
/* dst_portid and dst_group can be read locklessly */
WRITE_ONCE(nlk->dst_portid, nladdr->nl_pid);
WRITE_ONCE(nlk->dst_group, ffs(nladdr->nl_groups));
@@ -1165,8 +1167,8 @@ static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid)
/* Don't bother queuing skb if kernel socket has no input function */
nlk = nlk_sk(sock);
- /* dst_portid can be changed in netlink_connect() */
- if (sock->sk_state == NETLINK_CONNECTED &&
+ /* dst_portid and sk_state can be changed in netlink_connect() */
+ if (READ_ONCE(sock->sk_state) == NETLINK_CONNECTED &&
READ_ONCE(nlk->dst_portid) != nlk_sk(ssk)->portid) {
sock_put(sock);
return ERR_PTR(-ECONNREFUSED);