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amt: use READ_ONCE() in amt module 

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: cbc21dc1cf ("amt: add data plane of amt interface")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Taehee Yoo 2022-07-17 16:09:05 +00:00 committed by Paolo Abeni
parent 9c343ea618
commit 928f353cb8
1 changed files with 8 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
drivers/net/amt.c
View File

@ -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: