3.16.61-rc1 review patch. If anyone has any objections, please let me know.

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From: Sven Eckelmann sven@narfation.org

commit 3c12d0486856b9eb89c2a9ac336713cba90813e3 upstream.

Most of the implementations behind cfg80211_get_station will not initialize sinfo to zero before manipulating it. For example, the member "filled", which indicates the filled in parts of this struct, is often only modified by enabling certain bits in the bitfield while keeping the remaining bits in their original state. A caller without a preinitialized sinfo.filled can then no longer decide which parts of sinfo were filled in by cfg80211_get_station (or actually the underlying implementations).

cfg80211_get_station must therefore take care that sinfo is initialized to zero. Otherwise, the caller may tries to read information which was not filled in and which must therefore also be considered uninitialized. In batadv_v_elp_get_throughput's case, an invalid "random" expected throughput may be stored for this neighbor and thus the B.A.T.M.A.N V algorithm may switch to non-optimal neighbors for certain destinations.

Fixes: 7406353d43c8 ("cfg80211: implement cfg80211_get_station cfg80211 API") Reported-by: Thomas Lauer holminateur@gmail.com Reported-by: Marcel Schmidt ff.z-casparistrasse@mailbox.org Cc: b.a.t.m.a.n@lists.open-mesh.org Signed-off-by: Sven Eckelmann sven@narfation.org Signed-off-by: Johannes Berg johannes@sipsolutions.net Signed-off-by: Ben Hutchings ben@decadent.org.uk --- net/wireless/util.c | 2 ++ 1 file changed, 2 insertions(+)

--- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -1566,6 +1566,8 @@ int cfg80211_get_station(struct net_devi if (!rdev->ops->get_station) return -EOPNOTSUPP;

+ memset(sinfo, 0, sizeof(*sinfo)); + return rdev_get_station(rdev, dev, mac_addr, sinfo); } EXPORT_SYMBOL(cfg80211_get_station);