Commit 3207390a authored Oct 06, 2010 by Johannes Berg Committed by John W. Linville Oct 06, 2010

cfg80211: fix BSS double-unlinking



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.

Cc: stable@kernel.org
Reported-by: Ben Greear <greearb@candelatech.com>
Tested-by: Hun-Kyi Wynn <hkwynn@candelatech.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

parent b206b4ef

net/wireless/scan.c

+6 −6

Original line number	Diff line number	Diff line
		@@ -650,15 +650,15 @@ 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);

		list_del(&bss->list);
		if (!list_empty(&bss->list)) {
		list_del_init(&bss->list);
		dev->bss_generation++;
		rb_erase(&bss->rbn, &dev->bss_tree);

		spin_unlock_bh(&dev->bss_lock);

		kref_put(&bss->ref, bss_release);
		}
		spin_unlock_bh(&dev->bss_lock);
		}
		EXPORT_SYMBOL(cfg80211_unlink_bss);

		#ifdef CONFIG_CFG80211_WEXT

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