Commit c319d50b authored Jul 30, 2013 by Johannes Berg

nl80211: fix another nl80211_fam.attrbuf race



This is similar to the race Linus had reported, but in this case
it's an older bug: nl80211_prepare_wdev_dump() uses the wiphy
index in cb->args[0] as it is and thus parses the message over
and over again instead of just once because 0 is the first valid
wiphy index. Similar code in nl80211_testmode_dump() correctly
offsets the wiphy_index by 1, do that here as well.

Cc: stable@vger.kernel.org
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

parent 23df0b73

net/wireless/nl80211.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -441,10 +441,12 @@ static int nl80211_prepare_wdev_dump(struct sk_buff *skb,
		goto out_unlock;
		}
		rdev = wiphy_to_dev((wdev)->wiphy);
		cb->args[0] = (*rdev)->wiphy_idx;
		/* 0 is the first index - add 1 to parse only once */
		cb->args[0] = (*rdev)->wiphy_idx + 1;
		cb->args[1] = (*wdev)->identifier;
		} else {
		struct wiphy *wiphy = wiphy_idx_to_wiphy(cb->args[0]);
		/* subtract the 1 again here */
		struct wiphy *wiphy = wiphy_idx_to_wiphy(cb->args[0] - 1);
		struct wireless_dev *tmp;

		if (!wiphy) {