From c926d006c1514cfb3572893f41f2324e96823661 Mon Sep 17 00:00:00 2001 From: Tim Harvey Date: Thu, 9 Dec 2010 10:43:13 -0800 Subject: [PATCH] mac80211: Fix NULL-pointer deference on ibss merge when not ready dev_open will eventually call ieee80211_ibss_join which sets up the skb used for beacons/probe-responses however it is possible to receive beacons that attempt to merge before this occurs causing a null pointer dereference. Check ssid_len as that is the last thing set in ieee80211_ibss_join. This occurs quite easily in the presence of adhoc nodes with hidden SSID's revised previous patch to check further up based on irc feedback Signed-off-by: Tim Harvey Reviewed-by: Johannes Berg Signed-off-by: John W. Linville --- net/mac80211/ibss.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c index 239c4836a946..077a93dd1671 100644 --- a/net/mac80211/ibss.c +++ b/net/mac80211/ibss.c @@ -780,6 +780,9 @@ void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, mutex_lock(&sdata->u.ibss.mtx); + if (!sdata->u.ibss.ssid_len) + goto mgmt_out; /* not ready to merge yet */ + switch (fc & IEEE80211_FCTL_STYPE) { case IEEE80211_STYPE_PROBE_REQ: ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len); @@ -797,6 +800,7 @@ void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, break; } + mgmt_out: mutex_unlock(&sdata->u.ibss.mtx); }