From d62890885efbc48acea46964ea3af69b61c8c5eb Mon Sep 17 00:00:00 2001
From: Sven Eckelmann <sven@narfation.org>
Date: Fri, 9 Jun 2017 17:06:51 +0200
Subject: [PATCH] batman-adv: Accept only filled wifi station info
Git-commit: d62890885efbc48acea46964ea3af69b61c8c5eb
Patch-mainline: v4.13-rc1
References: bsc#1051510

The wifi driver can decide to not provide parts of the station info. For
example, the expected throughput of the station can be omitted when the
used rate control doesn't provide this kind of information.

The B.A.T.M.A.N. V implementation must therefore check the filled bitfield
before it tries to access the expected_throughput of the returned
station_info.

Reported-by: Alvaro Antelo <alvaro.antelo@gmail.com>
Fixes: c833484e5f38 ("batman-adv: ELP - compute the metric based on the estimated throughput")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Reviewed-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 net/batman-adv/bat_v_elp.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/batman-adv/bat_v_elp.c b/net/batman-adv/bat_v_elp.c
index 96e7333764f0..b58007b79e3a 100644
--- a/net/batman-adv/bat_v_elp.c
+++ b/net/batman-adv/bat_v_elp.c
@@ -19,6 +19,7 @@
 #include "main.h"
 
 #include <linux/atomic.h>
+#include <linux/bitops.h>
 #include <linux/byteorder/generic.h>
 #include <linux/errno.h>
 #include <linux/etherdevice.h>
@@ -29,6 +30,7 @@
 #include <linux/kernel.h>
 #include <linux/kref.h>
 #include <linux/netdevice.h>
+#include <linux/nl80211.h>
 #include <linux/random.h>
 #include <linux/rculist.h>
 #include <linux/rcupdate.h>
@@ -111,6 +113,8 @@ static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh)
 		}
 		if (ret)
 			goto default_throughput;
+		if (!(sinfo.filled & BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT)))
+			goto default_throughput;
 
 		return sinfo.expected_throughput / 100;
 	}
-- 
2.18.0