linux-stable.git/net/wireless, branch v3.16.40

cfg80211: limit scan results cache size

2017-02-23T03:54:37+00:00

commit 9853a55ef1bb66d7411136046060bbfb69c714fa upstream.

It's possible to make scanning consume almost arbitrary amounts
of memory, e.g. by sending beacon frames with random BSSIDs at
high rates while somebody is scanning.

Limit the number of BSS table entries we're willing to cache to
1000, limiting maximum memory usage to maybe 4-5MB, but lower
in practice - that would be the case for having both full-sized
beacon and probe response frames for each entry; this seems not
possible in practice, so a limit of 1000 entries will likely be
closer to 0.5 MB.

Signed-off-by: Johannes Berg 
Signed-off-by: Ben Hutchings

nl80211: validate number of probe response CSA counters

2016-11-20T01:17:26+00:00

commit ad5987b47e96a0fb6d13fea250e936aed000093c upstream.

Due to an apparent copy/paste bug, the number of counters for the
beacon configuration were checked twice, instead of checking the
number of probe response counters. Fix this to check the number of
probe response counters before parsing those.

Fixes: 9a774c78e211 ("cfg80211: Support multiple CSA counters")
Signed-off-by: Johannes Berg 
Signed-off-by: Ben Hutchings

nl80211: check netlink protocol in socket release notification

2016-06-15T20:29:22+00:00

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

cfg80211/wext: fix message ordering

2016-03-24T10:01:07+00:00

commit cb150b9d23be6ee7f3a0fff29784f1c5b5ac514d upstream.

Since cfg80211 frequently takes actions from its netdev notifier
call, wireless extensions messages could still be ordered badly
since the wext netdev notifier, since wext is built into the
kernel, runs before the cfg80211 netdev notifier. For example,
the following can happen:

5: wlan1:  mtu 1500 qdisc mq state DOWN group default
    link/ether 02:00:00:00:01:00 brd ff:ff:ff:ff:ff:ff
5: wlan1: 
    link/ether

when setting the interface down causes the wext message.

To also fix this, export the wireless_nlevent_flush() function
and also call it from the cfg80211 notifier.

Signed-off-by: Johannes Berg 
Signed-off-by: Luis Henriques

wext: fix message delay/ordering

2016-03-24T10:01:06+00:00

commit 8bf862739a7786ae72409220914df960a0aa80d8 upstream.

Beniamino reported that he was getting an RTM_NEWLINK message for a
given interface, after the RTM_DELLINK for it. It turns out that the
message is a wireless extensions message, which was sent because the
interface had been connected and disconnection while it was deleted
caused a wext message.

For its netlink messages, wext uses RTM_NEWLINK, but the message is
without all the regular rtnetlink attributes, so "ip monitor link"
prints just rudimentary information:

5: wlan1:  mtu 1500 qdisc mq state DOWN group default
    link/ether 02:00:00:00:01:00 brd ff:ff:ff:ff:ff:ff
Deleted 5: wlan1:  mtu 1500 qdisc noop state DOWN group default
    link/ether 02:00:00:00:01:00 brd ff:ff:ff:ff:ff:ff
5: wlan1: 
    link/ether
(from my hwsim reproduction)

This can cause userspace to get confused since it doesn't expect an
RTM_NEWLINK message after RTM_DELLINK.

The reason for this is that wext schedules a worker to send out the
messages, and the scheduling delay can cause the messages to get out
to userspace in different order.

To fix this, have wext register a netdevice notifier and flush out
any pending messages when netdevice state changes. This fixes any
ordering whenever the original message wasn't sent by a notifier
itself.

Reported-by: Beniamino Galvani 
Signed-off-by: Johannes Berg 
Signed-off-by: Luis Henriques

cfg80211: ignore netif running state when changing iftype

2015-07-15T09:01:22+00:00

commit 6cbfb1bb66e4e85da5db78e8ff429a85bd84ce64 upstream.

It was possible for mac80211 to be coerced into an
unexpected flow causing sdata union to become
corrupted. Station pointer was put into
sdata->u.vlan.sta memory location while it was
really master AP's sdata->u.ap.next_beacon. This
led to station entry being later freed as
next_beacon before __sta_info_flush() in
ieee80211_stop_ap() and a subsequent invalid
pointer dereference crash.

The problem was that ieee80211_ptr->use_4addr
wasn't cleared on interface type changes.

This could be reproduced with the following steps:

 # host A and host B have just booted; no
 # wpa_s/hostapd running; all vifs are down
 host A> iw wlan0 set type station
 host A> iw wlan0 set 4addr on
 host A> printf 'interface=wlan0\nssid=4addrcrash\nchannel=1\nwds_sta=1' > /tmp/hconf
 host A> hostapd -B /tmp/conf
 host B> iw wlan0 set 4addr on
 host B> ifconfig wlan0 up
 host B> iw wlan0 connect -w hostAssid
 host A> pkill hostapd
 # host A crashed:

 [  127.928192] BUG: unable to handle kernel NULL pointer dereference at 00000000000006c8
 [  127.929014] IP: [] __sta_info_flush+0xac/0x158
 ...
 [  127.934578]  [] ieee80211_stop_ap+0x139/0x26c
 [  127.934578]  [] ? dump_trace+0x279/0x28a
 [  127.934578]  [] __cfg80211_stop_ap+0x84/0x191
 [  127.934578]  [] cfg80211_stop_ap+0x3f/0x58
 [  127.934578]  [] nl80211_stop_ap+0x1b/0x1d
 [  127.934578]  [] genl_family_rcv_msg+0x259/0x2b5

Note: This isn't a revert of f8cdddb8d61d
("cfg80211: check iface combinations only when
iface is running") as far as functionality is
considered because b6a550156bc ("cfg80211/mac80211:
move more combination checks to mac80211") moved
the logic somewhere else already.

Fixes: f8cdddb8d61d ("cfg80211: check iface combinations only when iface is running")
Signed-off-by: Michal Kazior 
Signed-off-by: Johannes Berg 
Signed-off-by: Luis Henriques

cfg80211: wext: clear sinfo struct before calling driver

2015-06-30T16:15:23+00:00

commit 9c5a18a31b321f120efda412281bb9f610f84aa0 upstream.

Until recently, mac80211 overwrote all the statistics it could
provide when getting called, but it now relies on the struct
having been zeroed by the caller. This was always the case in
nl80211, but wext used a static struct which could even cause
values from one device leak to another.

Using a static struct is OK (as even documented in a comment)
since the whole usage of this function and its return value is
always locked under RTNL. Not clearing the struct for calling
the driver has always been wrong though, since drivers were
free to only fill values they could report, so calling this
for one device and then for another would always have leaked
values from one to the other.

Fix this by initializing the structure in question before the
driver method call.

This fixes https://bugzilla.kernel.org/show_bug.cgi?id=99691

Reported-by: Gerrit Renker 
Reported-by: Alexander Kaltsas 
Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller 
Signed-off-by: Luis Henriques

nl80211: ignore HT/VHT capabilities without QoS/WMM

2015-03-30T10:11:37+00:00

commit 496fcc294daab18799e190c0264863d653588d1f upstream.

As HT/VHT depend heavily on QoS/WMM, it's not a good idea to
let userspace add clients that have HT/VHT but not QoS/WMM.
Since it does so in certain cases we've observed (client is
using HT IEs but not QoS/WMM) just ignore the HT/VHT info at
this point and don't pass it down to the drivers which might
unconditionally use it.

Signed-off-by: Johannes Berg 
Signed-off-by: Luis Henriques

nl80211: fix per-station group key get/del and memory leak

2015-02-04T10:58:10+00:00

commit 0fa7b39131576dd1baa6ca17fca53c65d7f62249 upstream.

In case userspace attempts to obtain key information for or delete a
unicast key, this is currently erroneously rejected unless the driver
sets the WIPHY_FLAG_IBSS_RSN flag. Apparently enough drivers do so it
was never noticed.

Fix that, and while at it fix a potential memory leak: the error path
in the get_key() function was placed after allocating a message but
didn't free it - move it to a better place. Luckily admin permissions
are needed to call this operation.

Fixes: e31b82136d1ad ("cfg80211/mac80211: allow per-station GTKs")
Signed-off-by: Johannes Berg 
Signed-off-by: Luis Henriques

cfg80211: don't WARN about two consecutive Country IE hint

2015-01-15T10:44:04+00:00

commit 70dcec5a488a7b81779190ac8089475fe4b8b962 upstream.

This can happen and there is no point in added more
detection code lower in the stack. Catching these in one
single point (cfg80211) is enough. Stop WARNING about this
case.

This fixes:
https://bugzilla.kernel.org/show_bug.cgi?id=89001

Fixes: 2f1c6c572d7b ("cfg80211: process non country IE conflicting first")
Signed-off-by: Emmanuel Grumbach 
Signed-off-by: Johannes Berg 
Signed-off-by: Luis Henriques