[PATCH 5.2 125/143] mac80211: fix possible sta leak

From: Greg Kroah-Hartman
Date: Wed Sep 04 2019 - 14:16:28 EST


From: Johannes Berg <johannes.berg@xxxxxxxxx>

commit 5fd2f91ad483baffdbe798f8a08f1b41442d1e24 upstream.

If TDLS station addition is rejected, the sta memory is leaked.
Avoid this by moving the check before the allocation.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 7ed5285396c2 ("mac80211: don't initiate TDLS connection if station is not associated to AP")
Link: https://lore.kernel.org/r/20190801073033.7892-1-johannes@xxxxxxxxxxxxxxxx
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/mac80211/cfg.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1543,6 +1543,11 @@ static int ieee80211_add_station(struct
if (is_multicast_ether_addr(mac))
return -EINVAL;

+ if (params->sta_flags_set & BIT(NL80211_STA_FLAG_TDLS_PEER) &&
+ sdata->vif.type == NL80211_IFTYPE_STATION &&
+ !sdata->u.mgd.associated)
+ return -EINVAL;
+
sta = sta_info_alloc(sdata, mac, GFP_KERNEL);
if (!sta)
return -ENOMEM;
@@ -1550,10 +1555,6 @@ static int ieee80211_add_station(struct
if (params->sta_flags_set & BIT(NL80211_STA_FLAG_TDLS_PEER))
sta->sta.tdls = true;

- if (sta->sta.tdls && sdata->vif.type == NL80211_IFTYPE_STATION &&
- !sdata->u.mgd.associated)
- return -EINVAL;
-
err = sta_apply_parameters(local, sta, params);
if (err) {
sta_info_free(local, sta);