nl80211: always check nla_nest_start() return value

If the message got full during nla_nest_start(), it can return
NULL. None of the cases here seem like that can really happen,
but check the return value nonetheless.

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

1 files changed, 11 insertions, 0 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index f2a77c3daa59..60c8a7429d33 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -8022,6 +8022,8 @@ __cfg80211_alloc_vendor_skb(struct cfg80211_registered_device *rdev,
         }
 
         data = nla_nest_start(skb, attr);
+        if (!data)
+                goto nla_put_failure;
 
         ((void **)skb->cb)[0] = rdev;
         ((void **)skb->cb)[1] = hdr;
@@ -9458,8 +9460,14 @@ static int nl80211_send_wowlan_nd(struct sk_buff *msg,
 
         if (req->n_match_sets) {
                 matches = nla_nest_start(msg, NL80211_ATTR_SCHED_SCAN_MATCH);
+                if (!matches)
+                        return -ENOBUFS;
+
                 for (i = 0; i < req->n_match_sets; i++) {
                         match = nla_nest_start(msg, i);
+                        if (!match)
+                                return -ENOBUFS;
+
                         nla_put(msg, NL80211_SCHED_SCAN_MATCH_ATTR_SSID,
                                 req->match_sets[i].ssid.ssid_len,
                                 req->match_sets[i].ssid.ssid);
@@ -9474,6 +9482,9 @@ static int nl80211_send_wowlan_nd(struct sk_buff *msg,
 
         for (i = 0; i < req->n_scan_plans; i++) {
                 scan_plan = nla_nest_start(msg, i + 1);
+                if (!scan_plan)
+                        return -ENOBUFS;
+
                 if (!scan_plan ||
                     nla_put_u32(msg, NL80211_SCHED_SCAN_PLAN_INTERVAL,
                                 req->scan_plans[i].interval) ||