Messages in this thread Patch in this message | | | From | Kamal Mostafa <> | Subject | [PATCH 4.2.y-ckt 39/93] nl80211: check netlink protocol in socket release notification | Date | Tue, 26 Apr 2016 11:16:39 -0700 |
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4.2.8-ckt9 -stable review patch. If anyone has any objections, please let me know.
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From: Dmitry Ivanov <dmitrijs.ivanovs@ubnt.com>
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 <dima@ubnt.com> [rewrite commit message] Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- net/wireless/nl80211.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index d059cf3..517ecf1 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -12780,7 +12780,7 @@ static int nl80211_netlink_notify(struct notifier_block * nb, struct wireless_dev *wdev; struct cfg80211_beacon_registration *reg, *tmp; - if (state != NETLINK_URELEASE) + if (state != NETLINK_URELEASE || notify->protocol != NETLINK_GENERIC) return NOTIFY_DONE; rcu_read_lock(); -- 2.7.4
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