From 7400f42e9d765fa0656b432f3ab1245f9710f190 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Sat, 31 Oct 2009 07:40:37 +0100 Subject: [PATCH] cfg80211: fix NULL ptr deref commit 211a4d12abf86fe0df4cd68fc6327cbb58f56f81 Author: Johannes Berg Date: Tue Oct 20 15:08:53 2009 +0900 cfg80211: sme: deauthenticate on assoc failure introduced a potential NULL pointer dereference that some people have been hitting for some reason -- the params.bssid pointer is not guaranteed to be non-NULL for what seems to be a race between various ways of reaching the same thing. While I'm trying to analyse the problem more let's first fix the crash. I think the real fix may be to avoid doing _anything_ if it ended up being NULL, but right now I'm not sure yet. I think http://bugzilla.kernel.org/show_bug.cgi?id=14342 might also be this issue. Reported-by: Parag Warudkar Tested-by: Parag Warudkar Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- net/wireless/sme.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/wireless/sme.c b/net/wireless/sme.c index ece378d531ef..9f0b2800a9d7 100644 --- a/net/wireless/sme.c +++ b/net/wireless/sme.c @@ -165,7 +165,7 @@ void cfg80211_conn_work(struct work_struct *work) struct cfg80211_registered_device *rdev = container_of(work, struct cfg80211_registered_device, conn_work); struct wireless_dev *wdev; - u8 bssid[ETH_ALEN]; + u8 bssid_buf[ETH_ALEN], *bssid = NULL; rtnl_lock(); cfg80211_lock_rdev(rdev); @@ -181,7 +181,10 @@ void cfg80211_conn_work(struct work_struct *work) wdev_unlock(wdev); continue; } - memcpy(bssid, wdev->conn->params.bssid, ETH_ALEN); + if (wdev->conn->params.bssid) { + memcpy(bssid_buf, wdev->conn->params.bssid, ETH_ALEN); + bssid = bssid_buf; + } if (cfg80211_conn_do_work(wdev)) __cfg80211_connect_result( wdev->netdev, bssid, -- 2.20.1