mac80211: sanity check for null SSID
While associated we should never have empty SSID, but life can be full
of surprises, and is allways better to print a warning than crash.
Before memcpy() in ieee80211_probereq_get() check ssid_len instead of
ssid pointer, sice pointer it always passed by "ssidie + 2" expression
to send probe functions, so practically never can be NULL.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 93d484c..12ca982 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1518,9 +1518,16 @@
ifmgd->nullfunc_failed = false;
ieee80211_send_nullfunc(sdata->local, sdata, 0);
} else {
+ int ssid_len;
+
ssid = ieee80211_bss_get_ie(ifmgd->associated, WLAN_EID_SSID);
- ieee80211_send_probe_req(sdata, dst, ssid + 2, ssid[1], NULL, 0,
- (u32) -1, true, false);
+ if (WARN_ON_ONCE(ssid == NULL))
+ ssid_len = 0;
+ else
+ ssid_len = ssid[1];
+
+ ieee80211_send_probe_req(sdata, dst, ssid + 2, ssid_len, NULL,
+ 0, (u32) -1, true, false);
}
ifmgd->probe_send_count++;
@@ -1596,6 +1603,7 @@
struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
struct sk_buff *skb;
const u8 *ssid;
+ int ssid_len;
if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_STATION))
return NULL;
@@ -1606,8 +1614,13 @@
return NULL;
ssid = ieee80211_bss_get_ie(ifmgd->associated, WLAN_EID_SSID);
+ if (WARN_ON_ONCE(ssid == NULL))
+ ssid_len = 0;
+ else
+ ssid_len = ssid[1];
+
skb = ieee80211_build_probe_req(sdata, ifmgd->associated->bssid,
- (u32) -1, ssid + 2, ssid[1],
+ (u32) -1, ssid + 2, ssid_len,
NULL, 0, true);
return skb;