From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Johannes Berg" , "Dmitry Ivanov" , "Dmitry Ivanov" Date: Sun, 12 Jun 2016 22:34:41 +0100 Message-ID: Subject: [PATCH 3.2 13/46] nl80211: check netlink protocol in socket release notification In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.2.81-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Dmitry Ivanov commit 8f815cdde3e550e10c2736990d791f60c2ce43eb upstream. A non-privileged user can create a netlink socket with the same port_id as used by an existing open nl80211 netlink socket (e.g. as used by a hostapd process) with a different protocol number. Closing this socket will then lead to the notification going to nl80211's socket release notification handler, and possibly cause an action such as removing a virtual interface. Fix this issue by checking that the netlink protocol is NETLINK_GENERIC. Since generic netlink has no notifier chain of its own, we can't fix the problem more generically. Fixes: 026331c4d9b5 ("cfg80211/mac80211: allow registering for and sending action frames") Signed-off-by: Dmitry Ivanov [rewrite commit message] Signed-off-by: Johannes Berg Signed-off-by: Ben Hutchings --- net/wireless/nl80211.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -7496,7 +7496,7 @@ static int nl80211_netlink_notify(struct struct cfg80211_registered_device *rdev; struct wireless_dev *wdev; - if (state != NETLINK_URELEASE) + if (state != NETLINK_URELEASE || notify->protocol != NETLINK_GENERIC) return NOTIFY_DONE; rcu_read_lock();