linux-toradex.git/net/mac80211, branch v3.2.73

mac80211: enable assoc check for mesh interfaces

2015-10-13T02:46:04+00:00

commit 3633ebebab2bbe88124388b7620442315c968e8f upstream.

We already set a station to be associated when peering completes, both
in user space and in the kernel.  Thus we should always have an
associated sta before sending data frames to that station.

Failure to check assoc state can cause crashes in the lower-level driver
due to transmitting unicast data frames before driver sta structures
(e.g. ampdu state in ath9k) are initialized.  This occurred when
forwarding in the presence of fixed mesh paths: frames were transmitted
to stations with whom we hadn't yet completed peering.

Reported-by: Alexis Green 
Tested-by: Jesse Jones 
Signed-off-by: Bob Copeland 
Signed-off-by: Johannes Berg 
Signed-off-by: Ben Hutchings

mac80211: clear subdir_stations when removing debugfs

2015-08-12T14:33:22+00:00

commit 4479004e6409087d1b4986881dc98c6c15dffb28 upstream.

If we don't do this, and we then fail to recreate the debugfs
directory during a mode change, then we will fail later trying
to add stations to this now bogus directory:

BUG: unable to handle kernel NULL pointer dereference at 0000006c
IP: [] mutex_lock+0x12/0x30
Call Trace:
[] start_creating+0x44/0xc0
[] debugfs_create_dir+0x13/0xf0
[] ieee80211_sta_debugfs_add+0x6e/0x490 [mac80211]

Signed-off-by: Tom Hughes 
Signed-off-by: Johannes Berg 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

mac80211: move WEP tailroom size check

2015-08-06T23:32:10+00:00

commit 47b4e1fc4972cc43a19121bc2608a60aef3bf216 upstream.

Remove checking tailroom when adding IV as it uses only
headroom, and move the check to the ICV generation that
actually needs the tailroom.

In other case I hit such warning and datapath don't work,
when testing:
- IBSS + WEP
- ath9k with hw crypt enabled
- IPv6 data (ping6)

WARNING: CPU: 3 PID: 13301 at net/mac80211/wep.c:102 ieee80211_wep_add_iv+0x129/0x190 [mac80211]()
[...]
Call Trace:
[] dump_stack+0x45/0x57
[] warn_slowpath_common+0x8a/0xc0
[] warn_slowpath_null+0x1a/0x20
[] ieee80211_wep_add_iv+0x129/0x190 [mac80211]
[] ieee80211_crypto_wep_encrypt+0x6b/0xd0 [mac80211]
[] invoke_tx_handlers+0xc51/0xf30 [mac80211]
[...]

Signed-off-by: Janusz Dziedzic 
Signed-off-by: Johannes Berg 
[bwh: Backported to 3.2: s/IEEE80211_WEP/WEP/]
Signed-off-by: Ben Hutchings

mac80211: fix RX A-MPDU session reorder timer deletion

2015-05-09T22:16:34+00:00

commit 788211d81bfdf9b6a547d0530f206ba6ee76b107 upstream.

There's an issue with the way the RX A-MPDU reorder timer is
deleted that can cause a kernel crash like this:

 * tid_rx is removed - call_rcu(ieee80211_free_tid_rx)
 * station is destroyed
 * reorder timer fires before ieee80211_free_tid_rx() runs,
   accessing the station, thus potentially crashing due to
   the use-after-free

The station deletion is protected by synchronize_net(), but
that isn't enough -- ieee80211_free_tid_rx() need not have
run when that returns (it deletes the timer.) We could use
rcu_barrier() instead of synchronize_net(), but that's much
more expensive.

Instead, to fix this, add a field tracking that the session
is being deleted. In this case, the only re-arming of the
timer happens with the reorder spinlock held, so make that
code not rearm it if the session is being deleted and also
delete the timer after setting that field. This ensures the
timer cannot fire after ___ieee80211_stop_rx_ba_session()
returns, which fixes the problem.

Signed-off-by: Johannes Berg 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

mac80211: disable u-APSD queues by default

2015-05-09T22:16:26+00:00

commit aa75ebc275b2a91b193654a177daf900ad6703f0 upstream.

Some APs experience problems when working with
U-APSD. Decreasing the probability of that
happening by using legacy mode for all ACs but VO
isn't enough.

Cisco 4410N originally forced us to enable VO by
default only because it treated non-VO ACs as
legacy.

However some APs (notably Netgear R7000) silently
reclassify packets to different ACs. Since u-APSD
ACs require trigger frames for frame retrieval
clients would never see some frames (e.g. ARP
responses) or would fetch them accidentally after
a long time.

It makes little sense to enable u-APSD queues by
default because it needs userspace applications to
be aware of it to actually take advantage of the
possible additional powersavings. Implicitly
depending on driver autotrigger frame support
doesn't make much sense.

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

mac80211: set only VO as a U-APSD enabled AC

2015-05-09T22:16:26+00:00

commit d6a4ed6fe0a0d4790941e7f13e56630b8b9b053d upstream.

Some APs experience problems when working with U-APSD. Decrease the
probability of that happening by using legacy mode for all ACs but VO.

The AP that caused us troubles was a Cisco 4410N. It ignores our
setting, and always treats non-VO ACs as legacy.

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

mac80211: drop unencrypted frames in mesh fwding

2015-05-09T22:16:25+00:00

commit d0c22119f574b851e63360c6b8660fe9593bbc3c upstream.

The mesh forwarding path was not checking that data
frames were protected when running an encrypted network;
add the necessary check.

Reported-by: Johannes Berg 
Signed-off-by: Bob Copeland 
Signed-off-by: Johannes Berg 
Signed-off-by: Ben Hutchings

mac80211: Send EAPOL frames at lowest rate

2015-05-09T22:16:21+00:00

commit 9c1c98a3bb7b7593b60264b9a07e001e68b46697 upstream.

The current minstrel_ht rate control behavior is somewhat optimistic in
trying to find optimum TX rate. While this is usually fine for normal
Data frames, there are cases where a more conservative set of retry
parameters would be beneficial to make the connection more robust.

EAPOL frames are critical to the authentication and especially the
EAPOL-Key message 4/4 (the last message in the 4-way handshake) is
important to get through to the AP. If that message is lost, the only
recovery mechanism in many cases is to reassociate with the AP and start
from scratch. This can often be avoided by trying to send the frame with
more conservative rate and/or with more link layer retries.

In most cases, minstrel_ht is currently using the initial EAPOL-Key
frames for probing higher rates and this results in only five link layer
transmission attempts (one at high(ish) MCS and four at MCS0). While
this works with most APs, it looks like there are some deployed APs that
may have issues with the EAPOL frames using HT MCS immediately after
association. Similarly, there may be issues in cases where the signal
strength or radio environment is not good enough to be able to get
frames through even at couple of MCS 0 tries.

The best approach for this would likely to be to reduce the TX rate for
the last rate (3rd rate parameter in the set) to a low basic rate (say,
6 Mbps on 5 GHz and 2 or 5.5 Mbps on 2.4 GHz), but doing that cleanly
requires some more effort. For now, we can start with a simple one-liner
that forces the minimum rate to be used for EAPOL frames similarly how
the TX rate is selected for the IEEE 802.11 Management frames. This does
result in a small extra latency added to the cases where the AP would be
able to receive the higher rate, but taken into account how small number
of EAPOL frames are used, this is likely to be insignificant. A future
optimization in the minstrel_ht design can also allow this patch to be
reverted to get back to the more optimized initial TX rate.

It should also be noted that many drivers that do not use minstrel as
the rate control algorithm are already doing similar workarounds by
forcing the lowest TX rate to be used for EAPOL frames.

Reported-by: Linus Torvalds 
Tested-by: Linus Torvalds 
Signed-off-by: Jouni Malinen 
Signed-off-by: Johannes Berg 
[bwh: Backported to 3.2: adjust the controlling if-statement to make
 this work]
Signed-off-by: Ben Hutchings

mac80211: fix multicast LED blinking and counter

2015-02-20T00:49:30+00:00

commit d025933e29872cb1fe19fc54d80e4dfa4ee5779c upstream.

As multicast-frames can't be fragmented, "dot11MulticastReceivedFrameCount"
stopped being incremented after the use-after-free fix. Furthermore, the
RX-LED will be triggered by every multicast frame (which wouldn't happen
before) which wouldn't allow the LED to rest at all.

Fixes https://bugzilla.kernel.org/show_bug.cgi?id=89431 which also had the
patch.

Fixes: b8fff407a180 ("mac80211: fix use-after-free in defragmentation")
Signed-off-by: Andreas Müller 
[rewrite commit message]
Signed-off-by: Johannes Berg 
Signed-off-by: Ben Hutchings

mac80211: fix use-after-free in defragmentation

2014-12-14T16:23:54+00:00

commit b8fff407a180286aa683d543d878d98d9fc57b13 upstream.

Upon receiving the last fragment, all but the first fragment
are freed, but the multicast check for statistics at the end
of the function refers to the current skb (the last fragment)
causing a use-after-free bug.

Since multicast frames cannot be fragmented and we check for
this early in the function, just modify that check to also
do the accounting to fix the issue.

Reported-by: Yosef Khyal 
Signed-off-by: Johannes Berg 
Signed-off-by: Ben Hutchings