From: Johannes Berg Date: Tue, 7 Jul 2009 21:41:27 +0000 (+0200) Subject: cfg80211: fix race in giwrate X-Git-Tag: firefly_0821_release~12983^2~544^2~121 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=a71d62dbf3f0523b7a456333196cb26cf783fe92;p=firefly-linux-kernel-4.4.55.git cfg80211: fix race in giwrate cfg80211_wext_giwrate doesn't lock the wdev, so it cannot access current_bss race-free. Also, there's little point in trying to ask the driver for an AP that it never told us about, so avoid that case. Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c index 9d101d566bb1..5088d89a30fc 100644 --- a/net/wireless/wext-compat.c +++ b/net/wireless/wext-compat.c @@ -1127,7 +1127,7 @@ int cfg80211_wext_giwrate(struct net_device *dev, struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy); /* we are under RTNL - globally locked - so can use a static struct */ static struct station_info sinfo; - u8 *addr; + u8 addr[ETH_ALEN]; int err; if (wdev->iftype != NL80211_IFTYPE_STATION) @@ -1136,12 +1136,15 @@ int cfg80211_wext_giwrate(struct net_device *dev, if (!rdev->ops->get_station) return -EOPNOTSUPP; + err = 0; + wdev_lock(wdev); if (wdev->current_bss) - addr = wdev->current_bss->pub.bssid; - else if (wdev->wext.connect.bssid) - addr = wdev->wext.connect.bssid; + memcpy(addr, wdev->current_bss->pub.bssid, ETH_ALEN); else - return -EOPNOTSUPP; + err = -EOPNOTSUPP; + wdev_unlock(wdev); + if (err) + return err; err = rdev->ops->get_station(&rdev->wiphy, dev, addr, &sinfo); if (err)