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| author | Dmitry Ivanov <dmitrijs.ivanovs@ubnt.com> | 2016-04-06 17:23:18 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-05-04 14:51:24 -0700 |
| commit | 9b59ea7e026692145136a71f86df0ec2b3c15154 (patch) | |
| tree | 49872d0d9e87832e27208563ea35b229f0cf95e9 /net | |
| parent | fb8d8468d0da56f6b5eea1bae31492ca5253e3b3 (diff) | |
| download | lwn-9b59ea7e026692145136a71f86df0ec2b3c15154.tar.gz lwn-9b59ea7e026692145136a71f86df0ec2b3c15154.zip | |
nl80211: check netlink protocol in socket release notification
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/wireless/nl80211.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index c260243dbe07..7bf5f463566b 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -11522,7 +11522,7 @@ 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(); |