From 9f7551e05b0f59c09bf0ef8277e3364449feacb6 Mon Sep 17 00:00:00 2001 From: Reiter Wolfgang Date: Sat, 31 Dec 2016 21:11:57 +0100 Subject: [PATCH] drop_monitor: add missing call to genlmsg_end [ Upstream commit 4200462d88f47f3759bdf4705f87e207b0f5b2e4 ] Update nlmsg_len field with genlmsg_end to enable userspace processing using nlmsg_next helper. Also adds error handling. Signed-off-by: Reiter Wolfgang Acked-by: Neil Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/drop_monitor.c | 33 ++++++++++++++++++++++++--------- 1 file changed, 24 insertions(+), 9 deletions(-) diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c index 72cfb0c61125..5de61aaad586 100644 --- a/net/core/drop_monitor.c +++ b/net/core/drop_monitor.c @@ -80,6 +80,7 @@ static struct sk_buff *reset_per_cpu_data(struct per_cpu_dm_data *data) struct nlattr *nla; struct sk_buff *skb; unsigned long flags; + void *msg_header; al = sizeof(struct net_dm_alert_msg); al += dm_hit_limit * sizeof(struct net_dm_drop_point); @@ -87,17 +88,31 @@ static struct sk_buff *reset_per_cpu_data(struct per_cpu_dm_data *data) skb = genlmsg_new(al, GFP_KERNEL); - if (skb) { - genlmsg_put(skb, 0, 0, &net_drop_monitor_family, - 0, NET_DM_CMD_ALERT); - nla = nla_reserve(skb, NLA_UNSPEC, - sizeof(struct net_dm_alert_msg)); - msg = nla_data(nla); - memset(msg, 0, al); - } else { - mod_timer(&data->send_timer, jiffies + HZ / 10); + if (!skb) + goto err; + + msg_header = genlmsg_put(skb, 0, 0, &net_drop_monitor_family, + 0, NET_DM_CMD_ALERT); + if (!msg_header) { + nlmsg_free(skb); + skb = NULL; + goto err; + } + nla = nla_reserve(skb, NLA_UNSPEC, + sizeof(struct net_dm_alert_msg)); + if (!nla) { + nlmsg_free(skb); + skb = NULL; + goto err; } + msg = nla_data(nla); + memset(msg, 0, al); + genlmsg_end(skb, msg_header); + goto out; +err: + mod_timer(&data->send_timer, jiffies + HZ / 10); +out: spin_lock_irqsave(&data->lock, flags); swap(data->skb, skb); spin_unlock_irqrestore(&data->lock, flags); -- 2.39.5