nl80211: check nla_nest_start() return value

Coverity pointed out that we might dereference NULL later
if nla_nest_start() returns a failure. This isn't really
true since we'd bomb out before, but we should check the
return value directly, so do that.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index f1370ed..e20c27f 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -11094,6 +11094,8 @@ void cfg80211_report_wowlan_wakeup(struct wireless_dev *wdev,
                struct nlattr *reasons;
 
                reasons = nla_nest_start(msg, NL80211_ATTR_WOWLAN_TRIGGERS);
+               if (!reasons)
+                       goto free_msg;
 
                if (wakeup->disconnect &&
                    nla_put_flag(msg, NL80211_WOWLAN_TRIG_DISCONNECT))