[PATCH 4.9 12/70] nl80211: fix null-ptr dereference on invalid mesh configuration

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johannes Berg <johannes.berg@xxxxxxxxx>

commit 265698d7e6132a2d41471135534f4f36ad15b09c upstream.

If TX rates are specified during mesh join, the channel must
also be specified. Check the channel pointer to avoid a null
pointer dereference if it isn't.

Reported-by: Jouni Malinen <j@xxxxx>
Fixes: 8564e38206de ("cfg80211: add checks for beacon rate, extend to mesh")
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 net/wireless/nl80211.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -9481,6 +9481,9 @@ static int nl80211_join_mesh(struct sk_b
 		if (err)
 			return err;
 
+		if (!setup.chandef.chan)
+			return -EINVAL;
+
 		err = validate_beacon_tx_rate(rdev, setup.chandef.chan->band,
 					      &setup.beacon_rate);
 		if (err)