From: Taehee Yoo ap420073@gmail.com
[ Upstream commit 928f353cb8672f0d6078aad75eeec0ed33875b12 ]
There are some data races in the amt module. amt->ready4, amt->ready6, and amt->status can be accessed concurrently without locks. So, it uses READ_ONCE() and WRITE_ONCE().
Fixes: cbc21dc1cfe9 ("amt: add data plane of amt interface") Signed-off-by: Taehee Yoo ap420073@gmail.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/amt.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/drivers/net/amt.c b/drivers/net/amt.c index 615f26a553ae..ff859d4a4b50 100644 --- a/drivers/net/amt.c +++ b/drivers/net/amt.c @@ -584,7 +584,7 @@ static void amt_update_gw_status(struct amt_dev *amt, enum amt_status status, return; netdev_dbg(amt->dev, "Update GW status %s -> %s", status_str[amt->status], status_str[status]); - amt->status = status; + WRITE_ONCE(amt->status, status); }
static void __amt_update_relay_status(struct amt_tunnel_list *tunnel, @@ -958,8 +958,8 @@ static void amt_event_send_request(struct amt_dev *amt) if (amt->req_cnt > AMT_MAX_REQ_COUNT) { netdev_dbg(amt->dev, "Gateway is not ready"); amt->qi = AMT_INIT_REQ_TIMEOUT; - amt->ready4 = false; - amt->ready6 = false; + WRITE_ONCE(amt->ready4, false); + WRITE_ONCE(amt->ready6, false); amt->remote_ip = 0; amt_update_gw_status(amt, AMT_STATUS_INIT, false); amt->req_cnt = 0; @@ -1239,7 +1239,8 @@ static netdev_tx_t amt_dev_xmit(struct sk_buff *skb, struct net_device *dev) /* Gateway only passes IGMP/MLD packets */ if (!report) goto free; - if ((!v6 && !amt->ready4) || (v6 && !amt->ready6)) + if ((!v6 && !READ_ONCE(amt->ready4)) || + (v6 && !READ_ONCE(amt->ready6))) goto free; if (amt_send_membership_update(amt, skb, v6)) goto free; @@ -2368,7 +2369,7 @@ static bool amt_membership_query_handler(struct amt_dev *amt, ihv3 = skb_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS); skb_reset_transport_header(skb); skb_push(skb, sizeof(*iph) + AMT_IPHDR_OPTS); - amt->ready4 = true; + WRITE_ONCE(amt->ready4, true); amt->mac = amtmq->response_mac; amt->req_cnt = 0; amt->qi = ihv3->qqic; @@ -2391,7 +2392,7 @@ static bool amt_membership_query_handler(struct amt_dev *amt, mld2q = skb_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS); skb_reset_transport_header(skb); skb_push(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS); - amt->ready6 = true; + WRITE_ONCE(amt->ready6, true); amt->mac = amtmq->response_mac; amt->req_cnt = 0; amt->qi = mld2q->mld2q_qqic; @@ -2898,7 +2899,7 @@ static int amt_err_lookup(struct sock *sk, struct sk_buff *skb) break; case AMT_MSG_REQUEST: case AMT_MSG_MEMBERSHIP_UPDATE: - if (amt->status >= AMT_STATUS_RECEIVED_ADVERTISEMENT) + if (READ_ONCE(amt->status) >= AMT_STATUS_RECEIVED_ADVERTISEMENT) mod_delayed_work(amt_wq, &amt->req_wq, 0); break; default: