From 8c344624d82e34d805d9250b942158f652e9ac75 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 6 Oct 2010 21:18:04 +0200 Subject: [PATCH] cfg80211: fix BSS double-unlinking commit 3207390a8b58bfc1335750f91cf6783c48ca19ca upstream. When multiple interfaces are actively trying to associate with the same BSS, they may both find that the BSS isn't there and then try to unlink it. This can cause errors since the unlinking code can't currently deal with items that have already been unlinked. Normally this doesn't happen as most people don't try to use multiple station interfaces that associate at the same time too. Fix this by using the list entry as a flag to see if the item is still on a list. Reported-by: Ben Greear Tested-by: Hun-Kyi Wynn Signed-off-by: Johannes Berg Signed-off-by: John W. Linville Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen --- net/wireless/scan.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 5ca8c7180141..503ebb86ba18 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -650,14 +650,14 @@ void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub) bss = container_of(pub, struct cfg80211_internal_bss, pub); spin_lock_bh(&dev->bss_lock); + if (!list_empty(&bss->list)) { + list_del_init(&bss->list); + dev->bss_generation++; + rb_erase(&bss->rbn, &dev->bss_tree); - list_del(&bss->list); - dev->bss_generation++; - rb_erase(&bss->rbn, &dev->bss_tree); - + kref_put(&bss->ref, bss_release); + } spin_unlock_bh(&dev->bss_lock); - - kref_put(&bss->ref, bss_release); } EXPORT_SYMBOL(cfg80211_unlink_bss); -- 2.39.5