mac80211: Fix potential null pointer dereferencing

The patch "{nl,cfg,mac}80211: Implement RSSI threshold for mesh peering"
has a potential null pointer dereferencing problem. Thanks to Dan Carpenter
for pointing out. This patch will fix the issue.

Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Ashok Nagarajan 2012-03-06 12:48:30 -08:00 committed by John W. Linville
parent 2ef167557c
commit 3d4f969972

View File

@ -31,10 +31,11 @@
#define dot11MeshHoldingTimeout(s) (s->u.mesh.mshcfg.dot11MeshHoldingTimeout)
#define dot11MeshMaxPeerLinks(s) (s->u.mesh.mshcfg.dot11MeshMaxPeerLinks)
#define sta_meets_rssi_threshold(sta, sdata) \
/* We only need a valid sta if user configured a minimum rssi_threshold. */
#define rssi_threshold_check(sta, sdata) \
(sdata->u.mesh.mshcfg.rssi_threshold == 0 ||\
(s8) -ewma_read(&sta->avg_signal) > \
sdata->u.mesh.mshcfg.rssi_threshold)
(sta && (s8) -ewma_read(&sta->avg_signal) > \
sdata->u.mesh.mshcfg.rssi_threshold))
enum plink_event {
PLINK_UNDEFINED,
@ -307,7 +308,7 @@ void mesh_neighbour_update(u8 *hw_addr, u32 rates,
sta->plink_state == NL80211_PLINK_LISTEN &&
sdata->u.mesh.accepting_plinks &&
sdata->u.mesh.mshcfg.auto_open_plinks &&
sta_meets_rssi_threshold(sta, sdata))
rssi_threshold_check(sta, sdata))
mesh_plink_open(sta);
rcu_read_unlock();
@ -538,9 +539,9 @@ void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_m
}
if (ftype == WLAN_SP_MESH_PEERING_OPEN &&
!sta_meets_rssi_threshold(sta, sdata)) {
!rssi_threshold_check(sta, sdata)) {
mpl_dbg("Mesh plink: %pM does not meet rssi threshold\n",
sta->sta.addr);
mgmt->sa);
rcu_read_unlock();
return;
}