Commit Graph

153 Commits

Author SHA1 Message Date
Mathy Vanhoef
14f29a67f4 mac80211: prevent mixed key and fragment cache attacks
commit 94034c40ab4a3fcf581fbc7f8fdf4e29943c4a24 upstream.

Simultaneously prevent mixed key attacks (CVE-2020-24587) and fragment
cache attacks (CVE-2020-24586). This is accomplished by assigning a
unique color to every key (per interface) and using this to track which
key was used to decrypt a fragment. When reassembling frames, it is
now checked whether all fragments were decrypted using the same key.

To assure that fragment cache attacks are also prevented, the ID that is
assigned to keys is unique even over (re)associations and (re)connects.
This means fragments separated by a (re)association or (re)connect will
not be reassembled. Because mac80211 now also prevents the reassembly of
mixed encrypted and plaintext fragments, all cache attacks are prevented.

Cc: stable@vger.kernel.org
Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef@kuleuven.be>
Link: https://lore.kernel.org/r/20210511200110.3f8290e59823.I622a67769ed39257327a362cfc09c812320eb979@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-03 08:59:01 +02:00
Johannes Berg
d6b1f3fc76 mac80211: drop data frames without key on encrypted links
commit a0761a301746ec2d92d7fcb82af69c0a6a4339aa upstream.

If we know that we have an encrypted link (based on having had
a key configured for TX in the past) then drop all data frames
in the key selection handler if there's no key anymore.

This fixes an issue with mac80211 internal TXQs - there we can
buffer frames for an encrypted link, but then if the key is no
longer there when they're dequeued, the frames are sent without
encryption. This happens if a station is disconnected while the
frames are still on the TXQ.

Detecting that a link should be encrypted based on a first key
having been configured for TX is fine as there are no use cases
for a connection going from with encryption to no encryption.
With extended key IDs, however, there is a case of having a key
configured for only decryption, so we can't just trigger this
behaviour on a key being configured.

Cc: stable@vger.kernel.org
Reported-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200326150855.6865c7f28a14.I9fb1d911b064262d33e33dfba730cdeef83926ca@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-01 11:02:01 +02:00
Luca Coelho
753a9a729f mac80211: don't check if key is NULL in ieee80211_key_link()
We already assume that key is not NULL and dereference it in a few
other places before we check whether it is NULL, so the check is
unnecessary.  Remove it.

Fixes: 96fc6efb9a ("mac80211: IEEE 802.11 Extended Key ID support")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/20190830112451.21655-8-luca@coelho.fi
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-09-11 09:33:28 +02:00
Lior Cohen
624ff4b210 mac80211: clear crypto tx tailroom counter upon keys enable
In case we got a fw restart while roaming from encrypted AP to
non-encrypted one, we might end up with hitting a warning on the pending
counter crypto_tx_tailroom_pending_dec having a non-zero value.

The following comment taken from net/mac80211/key.c explains the rational
for the delayed tailroom needed:

	/*
	* The reason for the delayed tailroom needed decrementing is to
	* make roaming faster: during roaming, all keys are first deleted
	* and then new keys are installed. The first new key causes the
	* crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes
	* the cost of synchronize_net() (which can be slow). Avoid this
	* by deferring the crypto_tx_tailroom_needed_cnt decrementing on
	* key removal for a while, so if we roam the value is larger than
	* zero and no 0->1 transition happens.
	*
	* The cost is that if the AP switching was from an AP with keys
	* to one without, we still allocate tailroom while it would no
	* longer be needed. However, in the typical (fast) roaming case
	* within an ESS this usually won't happen.
	*/

The next flow lead to the warning eventually reported as a bug:
1. Disconnect from encrypted AP
2. Set crypto_tx_tailroom_pending_dec = 1 for the key
3. Schedule work
4. Reconnect to non-encrypted AP
5. Add a new key, setting the tailroom counter = 1
6. Got FW restart while pending counter is set ---> hit the warning

While on it, the ieee80211_reset_crypto_tx_tailroom() func was merged into
its single caller ieee80211_reenable_keys (previously called
ieee80211_enable_keys). Also, we reset the crypto_tx_tailroom_pending_dec
and remove the counters warning as we just reset both.

Signed-off-by: Lior Cohen <lior2.cohen@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/20190830112451.21655-7-luca@coelho.fi
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-09-11 09:33:28 +02:00
Johannes Berg
1c9559734e mac80211: remove unnecessary key condition
When we reach this point, the key cannot be NULL. Remove the condition
that suggests otherwise.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/20190830112451.21655-6-luca@coelho.fi
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-09-11 09:33:28 +02:00
Alexander Wetzel
dc3998ec5c mac80211: AMPDU handling for rekeys with Extended Key ID
Extended Key ID allows A-MPDU sessions while rekeying as long as each
A-MPDU aggregates only MPDUs with one keyid together.

Drivers able to segregate MPDUs accordingly can tell mac80211 to not
stop A-MPDU sessions when rekeying by setting the new flag
IEEE80211_HW_AMPDU_KEYBORDER_SUPPORT.

Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
Link: https://lore.kernel.org/r/20190629195015.19680-3-alexander@wetzel-home.de
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-07-26 13:29:10 +02:00
Alexander Wetzel
3e47bf1ca4 mac80211: Simplify Extended Key ID API
1) Drop IEEE80211_HW_EXT_KEY_ID_NATIVE and let drivers directly set
   the NL80211_EXT_FEATURE_EXT_KEY_ID flag.

2) Drop IEEE80211_HW_NO_AMPDU_KEYBORDER_SUPPORT and simply assume all
   drivers are unable to handle A-MPDU key borders.

The new Extended Key ID API now requires all mac80211 drivers to set
NL80211_EXT_FEATURE_EXT_KEY_ID when they implement set_key() and can
handle Extended Key ID. For drivers not providing set_key() mac80211
itself enables Extended Key ID support, using the internal SW crypto
services.

Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
Link: https://lore.kernel.org/r/20190629195015.19680-2-alexander@wetzel-home.de
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-07-26 13:28:59 +02:00
David S. Miller
92ad6325cb Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Minor SPDX change conflict.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-22 08:59:24 -04:00
Linus Torvalds
c884d8ac7f SPDX update for 5.2-rc6
Another round of SPDX updates for 5.2-rc6
 
 Here is what I am guessing is going to be the last "big" SPDX update for
 5.2.  It contains all of the remaining GPLv2 and GPLv2+ updates that
 were "easy" to determine by pattern matching.  The ones after this are
 going to be a bit more difficult and the people on the spdx list will be
 discussing them on a case-by-case basis now.
 
 Another 5000+ files are fixed up, so our overall totals are:
 	Files checked:            64545
 	Files with SPDX:          45529
 
 Compared to the 5.1 kernel which was:
 	Files checked:            63848
 	Files with SPDX:          22576
 This is a huge improvement.
 
 Also, we deleted another 20000 lines of boilerplate license crud, always
 nice to see in a diffstat.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'spdx-5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx

Pull still more SPDX updates from Greg KH:
 "Another round of SPDX updates for 5.2-rc6

  Here is what I am guessing is going to be the last "big" SPDX update
  for 5.2. It contains all of the remaining GPLv2 and GPLv2+ updates
  that were "easy" to determine by pattern matching. The ones after this
  are going to be a bit more difficult and the people on the spdx list
  will be discussing them on a case-by-case basis now.

  Another 5000+ files are fixed up, so our overall totals are:
	Files checked:            64545
	Files with SPDX:          45529

  Compared to the 5.1 kernel which was:
	Files checked:            63848
	Files with SPDX:          22576

  This is a huge improvement.

  Also, we deleted another 20000 lines of boilerplate license crud,
  always nice to see in a diffstat"

* tag 'spdx-5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx: (65 commits)
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 507
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 506
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 505
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 503
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 502
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 501
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 498
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 497
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 496
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 495
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 491
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 490
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 489
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 488
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 487
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 486
  treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 485
  ...
2019-06-21 09:58:42 -07:00
Thomas Gleixner
d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
David S. Miller
13091aa305 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Honestly all the conflicts were simple overlapping changes,
nothing really interesting to report.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-17 20:20:36 -07:00
Alexander Wetzel
90cc4bd611 mac80211: AMPDU handling for Extended Key ID
IEEE 802.11 - 2016 forbids mixing MPDUs with different keyIDs in one
A-MPDU. Drivers supporting A-MPDUs and Extended Key ID must actively
enforce that requirement due to the available two unicast keyIDs.

Allow driver to signal mac80211 that they will not check the keyID in
MPDUs when aggregating them and that they expect mac80211 to stop Tx
aggregation when rekeying a connection using Extended Key ID.

Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-06-14 14:05:35 +02:00
YueHaibing
818e9dfa2c mac80211: remove set but not used variable 'old'
Fixes gcc '-Wunused-but-set-variable' warning:

net/mac80211/key.c: In function 'ieee80211_set_tx_key':
net/mac80211/key.c:271:24: warning:
 variable 'old' set but not used [-Wunused-but-set-variable]

It is not used since introduction in
commit 96fc6efb9a ("mac80211: IEEE 802.11 Extended Key ID support")

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-05-24 11:26:44 +02:00
David S. Miller
30e5a9a5ba Various updates, notably:
* extended key ID support (from 802.11-2016)
  * per-STA TX power control support
  * mac80211 TX performance improvements
  * HE (802.11ax) updates
  * mesh link probing support
  * enhancements of multi-BSSID support (also related to HE)
  * OWE userspace processing support
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Merge tag 'mac80211-next-for-davem-2019-04-26' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next

Johannes Berg says:

====================
Various updates, notably:
 * extended key ID support (from 802.11-2016)
 * per-STA TX power control support
 * mac80211 TX performance improvements
 * HE (802.11ax) updates
 * mesh link probing support
 * enhancements of multi-BSSID support (also related to HE)
 * OWE userspace processing support
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-26 16:05:52 -04:00
Alexander Wetzel
96fc6efb9a mac80211: IEEE 802.11 Extended Key ID support
Add support for Extended Key ID as defined in IEEE 802.11-2016.

 - Implement the nl80211 API for Extended Key ID
 - Extend mac80211 API to allow drivers to support Extended Key ID
 - Enable Extended Key ID by default for drivers only supporting SW
   crypto (e.g. mac80211_hwsim)
 - Allow unicast Tx usage to be supressed (IEEE80211_KEY_FLAG_NO_AUTO_TX)
 - Select the decryption key based on the MPDU keyid
 - Enforce existing assumptions in the code that rekeys don't change the
   cipher

Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
[remove module parameter]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-04-26 13:02:11 +02:00
Alexander Wetzel
092c4098f2 mac80211: Optimize tailroom_needed update checks
Optimize/cleanup the delay tailroom checks and adds one missing tailroom
update.

Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-04-26 13:02:11 +02:00
Alexander Wetzel
78ad234152 mac80211: Honor SW_CRYPTO_CONTROL for unicast keys in AP VLAN mode
Restore SW_CRYPTO_CONTROL operation on AP_VLAN interfaces for unicast
keys, the original override was intended to be done for group keys as
those are treated specially by mac80211 and would always have been
rejected.

Now the situation is that AP_VLAN support must be enabled by the driver
if it can support it (meaning it can support software crypto GTK TX).

Thus, also simplify the code - if we get here with AP_VLAN and non-
pairwise key, software crypto must be used (driver doesn't know about
the interface) and can be used (driver must've advertised AP_VLAN if
it also uses SW_CRYPTO_CONTROL).

Fixes: db3bdcb9c3 ("mac80211: allow AP_VLAN operation on crypto controlled devices")
Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
[rewrite commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-04-09 13:40:32 +02:00
Gustavo A. R. Silva
40b5a0f8c6 mac80211: remove unnecessary NULL check
Both old and new cannot be NULL at the same time, hence checking
new when old is not NULL is unnecessary.

Also, notice that new is being dereferenced before it is checked:

	idx = new->conf.keyidx;

The above triggers a static code analysis warning.

Address this by removing the NULL check on new and adding a code
comment based on the following piece of code:

387        /* caller must provide at least one old/new */
388        if (WARN_ON(!new && !old))
389                return 0;

Addresses-Coverity-ID: 1473176 ("Dereference before null check")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2018-09-05 10:15:48 +02:00
Alexander Wetzel
62872a9b9a mac80211: Fix PTK rekey freezes and clear text leak
Rekeying PTK keys without "Extended Key ID for Individually Addressed
Frames" did use a procedure not suitable to replace in-use keys and
could caused the following issues:

 1) Freeze caused by incoming frames:
    If the local STA installed the key prior to the remote STA we still
    had the old key active in the hardware when mac80211 switched over
    to the new key.
    Therefore there was a window where the card could hand over frames
    decoded with the old key to mac80211 and bump the new PN (IV) value
    to an incorrect high number. When it happened the local replay
    detection silently started to drop all frames sent with the new key.

 2) Freeze caused by outgoing frames:
    If mac80211 was providing the PN (IV) and handed over a clear text
    frame for encryption to the hardware prior to a key change the
    driver/card could have processed the queued frame after switching
    to the new key. This bumped the PN value on the remote STA to an
    incorrect high number, tricking the remote STA to discard all frames
    we sent later.

 3) Freeze caused by RX aggregation reorder buffer:
    An aggregation session started with the old key and ending after the
    switch to the new key also bumped the PN to an incorrect high number,
    freezing the connection quite similar to 1).

 4) Freeze caused by repeating lost frames in an aggregation session:
    A driver could repeat a lost frame and encrypt it with the new key
    while in a TX aggregation session without updating the PN for the
    new key. This also could freeze connections similar to 2).

 5) Clear text leak:
    Removing encryption offload from the card cleared the encryption
    offload flag only after the card had deleted the key and we did not
    stop TX during the rekey. The driver/card could therefore get
    unencrypted frames from mac80211 while no longer be instructed to
    encrypt them.

To prevent those issues the key install logic has been changed:
 - Mac80211 divers known to be able to rekey PTK0 keys have to set
   @NL80211_EXT_FEATURE_CAN_REPLACE_PTK0,
 - mac80211 stops queuing frames depending on the key during the replace
 - the key is first replaced in the hardware and after that in mac80211
 - and mac80211 stops/blocks new aggregation sessions during the rekey.

For drivers not setting
@NL80211_EXT_FEATURE_CAN_REPLACE_PTK0 the user space must avoid PTK
rekeys if "Extended Key ID for Individually Addressed Frames" is not
being used. Rekeys for mac80211 drivers without this flag will generate a
warning and use an extra call to ieee80211_flush_queues() to both
highlight and try to prevent the issues with not updated drivers.

The core of the fix changes the key install procedure from:
 - atomic switch over to the new key in mac80211
 - remove the old key in the hardware (stops encryption offloading, fall
   back to software encryption with a potential clear text packet leak
   in between)
 - delete the inactive old key in mac80211
 - enable hardware encryption offloading for the new key
to:
 - if it's a PTK mark the old key as tainted to drop TX frames with the
   outgoing key
 - replace the key in hardware with the new one
 - atomic switch over to the new (not marked as tainted) key in
   mac80211 (which also resumes TX)
 - delete the inactive old key in mac80211

With the new sequence the hardware will be unable to decrypt frames
encrypted with the old key prior to switching to the new key in mac80211
and thus prevent PNs from packets decrypted with the old key to be
accounted against the new key.

For that to work the drivers have to provide a clear boundary.
Mac80211 drivers setting @NL80211_EXT_FEATURE_CAN_REPLACE_PTK0 confirm
to provide it and mac80211 will then be able to correctly rekey in-use
PTK keys with those drivers.

The mac80211 requirements for drivers to set the flag have been added to
the "Hardware crypto acceleration" documentation section. It drills down
to:
The drivers must not hand over frames decrypted with the old key to
mac80211 once the call to set_key() with %DISABLE_KEY has been
completed. It's allowed to either drop or continue to use the old key
for any outgoing frames which are already in the queues, but it must not
send out any of them unencrypted or encrypted with the new key.

Even with the new boundary in place aggregation sessions with the
reorder buffer are problematic:
RX aggregation session started prior and completed after the rekey could
still dump frames received with the old key at mac80211 after it
switched over to the new key. This is side stepped by stopping all (RX
and TX) aggregation sessions when replacing a PTK key and hardware key
offloading.
Stopping TX aggregation sessions avoids the need to get
the PNs (IVs) updated in frames prepared for the old key and
(re)transmitted after the switch to the new key. As a bonus it improves
the compatibility when the remote STA is not handling rekeys as it
should.

When using software crypto aggregation sessions are not stopped.
Mac80211 won't be able to decode the dangerous frames and discard them
without special handling.

Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
[trim overly long rekey warning]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2018-09-05 10:03:17 +02:00
Manikanta Pubbisetty
133bf90dbb mac80211: restrict delayed tailroom needed decrement
As explained in ieee80211_delayed_tailroom_dec(), during roam,
keys of the old AP will be destroyed and new keys will be
installed. Deletion of the old key causes
crypto_tx_tailroom_needed_cnt to go from 1 to 0 and the new key
installation causes a transition from 0 to 1.

Whenever crypto_tx_tailroom_needed_cnt transitions from 0 to 1,
we invoke synchronize_net(); the reason for doing this is to avoid
a race in the TX path as explained in increment_tailroom_need_count().
This synchronize_net() operation can be slow and can affect the station
roam time. To avoid this, decrementing the crypto_tx_tailroom_needed_cnt
is delayed for a while so that upon installation of new key the
transition would be from 1 to 2 instead of 0 to 1 and thereby
improving the roam time.

This is all correct for a STA iftype, but deferring the tailroom_needed
decrement for other iftypes may be unnecessary.

For example, let's consider the case of a 4-addr client connecting to
an AP for which AP_VLAN interface is also created, let the initial
value for tailroom_needed on the AP be 1.

* 4-addr client connects to the AP (AP: tailroom_needed = 1)
* AP will clear old keys, delay decrement of tailroom_needed count
* AP_VLAN is created, it takes the tailroom count from master
  (AP_VLAN: tailroom_needed = 1, AP: tailroom_needed = 1)
* Install new key for the station, assume key is plumbed in the HW,
  there won't be any change in tailroom_needed count on AP iface
* Delayed decrement of tailroom_needed count on AP
  (AP: tailroom_needed = 0, AP_VLAN: tailroom_needed = 1)

Because of the delayed decrement on AP iface, tailroom_needed count goes
out of sync between AP(master iface) and AP_VLAN(slave iface) and
there would be unnecessary tailroom created for the packets going
through AP_VLAN iface.

Also, WARN_ONs were observed while trying to bring down the AP_VLAN
interface:
(warn_slowpath_common) (warn_slowpath_null+0x18/0x20)
(warn_slowpath_null) (ieee80211_free_keys+0x114/0x1e4)
(ieee80211_free_keys) (ieee80211_del_virtual_monitor+0x51c/0x850)
(ieee80211_del_virtual_monitor) (ieee80211_stop+0x30/0x3c)
(ieee80211_stop) (__dev_close_many+0x94/0xb8)
(__dev_close_many) (dev_close_many+0x5c/0xc8)

Restricting delayed decrement to station interface alone fixes the problem
and it makes sense to do so because delayed decrement is done to improve
roam time which is applicable only for client devices.

Signed-off-by: Manikanta Pubbisetty <mpubbise@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2018-07-24 09:21:12 +02:00
Manikanta Pubbisetty
db3bdcb9c3 mac80211: allow AP_VLAN operation on crypto controlled devices
In the current implementation, mac80211 advertises the support of
AP_VLANs based on the driver's support for AP mode; it also
blocks encrypted AP_VLAN operation on devices advertising
SW_CRYPTO_CONTROL.

The implementation seems weird in it's current form and could be
often confusing, this is because there can be drivers advertising
both SW_CRYPTO_CONTROL and AP mode support (ex: ath10k) in which case
AP_VLAN will still be supported but only in open BSS and not in
secured BSS.

When SW_CRYPTO_CONTROL is enabled, it makes more sense if the decision
to support AP_VLANs is left to the driver. Mac80211 can then allow
AP_VLAN operations depending on the driver support.

Signed-off-by: Manikanta Pubbisetty <mpubbise@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2018-03-29 11:35:22 +02:00
David Spinadel
9de18d8186 mac80211: Add MIC space only for TX key option
Add a key flag to indicates that the device only needs
MIC space and not a real MIC.
In such cases, keep the MIC zeroed for ease of debug.

Signed-off-by: David Spinadel <david.spinadel@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2017-12-11 12:20:17 +01:00
Johannes Berg
cfbb0d90a7 mac80211: don't compare TKIP TX MIC key in reinstall prevention
For the reinstall prevention, the code I had added compares the
whole key. It turns out though that iwlwifi firmware doesn't
provide the TKIP TX MIC key as it's not needed in client mode,
and thus the comparison will always return false.

For client mode, thus always zero out the TX MIC key part before
doing the comparison in order to avoid accepting the reinstall
of the key with identical encryption and RX MIC key, but not the
same TX MIC key (since the supplicant provides the real one.)

Fixes: fdf7cb4185 ("mac80211: accept key reinstall without changing anything")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2017-10-25 11:04:45 +02:00
Jason A. Donenfeld
2bdd713b92 mac80211: use constant time comparison with keys
Otherwise we risk leaking information via timing side channel.

Fixes: fdf7cb4185 ("mac80211: accept key reinstall without changing anything")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2017-10-18 09:39:14 +02:00
Johannes Berg
fdf7cb4185 mac80211: accept key reinstall without changing anything
When a key is reinstalled we can reset the replay counters
etc. which can lead to nonce reuse and/or replay detection
being impossible, breaking security properties, as described
in the "KRACK attacks".

In particular, CVE-2017-13080 applies to GTK rekeying that
happened in firmware while the host is in D3, with the second
part of the attack being done after the host wakes up. In
this case, the wpa_supplicant mitigation isn't sufficient
since wpa_supplicant doesn't know the GTK material.

In case this happens, simply silently accept the new key
coming from userspace but don't take any action on it since
it's the same key; this keeps the PN replay counters intact.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2017-10-16 13:02:03 +02:00
Johannes Berg
ec4efc4a10 mac80211: don't call drv_set_default_unicast_key() for VLANs
Since drivers know nothing about AP_VLAN interfaces, trying to
call drv_set_default_unicast_key() just results in a warning
and no call to the driver. Avoid the warning by not calling the
driver for this on AP_VLAN interfaces.

This means that drivers that somehow need this call for AP mode
will fail to work properly in the presence of VLAN interfaces,
but the current drivers don't seem to use it, and mac80211 will
select and indicate the key - so drivers should be OK now.

Reported-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-12-13 15:57:59 +01:00
Johannes Berg
49ddf8e6e2 mac80211: add fast-rx path
The regular RX path has a lot of code, but with a few
assumptions on the hardware it's possible to reduce the
amount of code significantly. Currently the assumptions
on the driver are the following:
 * hardware/driver reordering buffer (if supporting aggregation)
 * hardware/driver decryption & PN checking (if using encryption)
 * hardware/driver did de-duplication
 * hardware/driver did A-MSDU deaggregation
 * AP_LINK_PS is used (in AP mode)
 * no client powersave handling in mac80211 (in client mode)

of which some are actually checked per packet:
 * de-duplication
 * PN checking
 * decryption
and additionally packets must
 * not be A-MSDU (have been deaggregated by driver/device)
 * be data packets
 * not be fragmented
 * be unicast
 * have RFC 1042 header

Additionally dynamically we assume:
 * no encryption or CCMP/GCMP, TKIP/WEP/other not allowed
 * station must be authorized
 * 4-addr format not enabled

Some data needed for the RX path is cached in a new per-station
"fast_rx" structure, so that we only need to look at this and
the packet, no other memory when processing packets on the fast
RX path.

After doing the above per-packet checks, the data path collapses
down to a pretty simple conversion function taking advantage of
the data cached in the small fast_rx struct.

This should speed up the RX processing, and will make it easier
to reason about parallelizing RX (for which statistics will need
to be per-CPU still.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-04-06 13:18:18 +02:00
Eliad Peller
ca48ebbc7e mac80211: remove ieee80211_get_key_tx_seq/ieee80211_set_key_tx_seq
Since the PNs of all the tx keys are now tracked in the public
part of the key struct (with atomic counter), we no longer
need these functions.

dvm and vt665{5,6} are currently the only users of these functions,
so update them accordingly.

Signed-off-by: Eliad Peller <eliadx.peller@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-02-24 09:04:39 +01:00
Eliad Peller
f8079d43cf mac80211: move TKIP TX IVs to public part of key struct
Some drivers/devices might want to set the IVs by
themselves (and still let mac80211 generate MMIC).

Specifically, this is needed when the device does
offloading at certain times, and the driver has
to make sure that the IVs of new tx frames (from
the host) are synchronized with IVs that were
potentially used during the offloading.

Similarly to CCMP, move the TX IVs of TKIP keys to the
public part of the key struct, and export a function
to add the IV right into the crypto header.

The public tx_pn field is defined as atomic64, so define
TKIP_PN_TO_IV16/32 helper macros to convert it to iv16/32
when needed.

Since the iv32 used for the p1k cache is taken
directly from the frame, we can safely remove
iv16/32 from being protected by tkip.txlock.

Signed-off-by: Eliad Peller <eliadx.peller@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-02-24 09:04:38 +01:00
Eliad Peller
ef044763a3 mac80211: add atomic uploaded keys iterator
add ieee80211_iter_keys_rcu() to iterate over uploaded
keys in atomic context (when rcu is locked)

The station removal code removes the keys only after
calling synchronize_net(), so it's not safe to iterate
the keys at this point (and postponing the actual key
deletion with call_rcu() might result in some
badly-ordered ops calls).

Add a flag to indicate a station is being removed,
and skip the configured keys if it's set.

Signed-off-by: Eliad Peller <eliadx.peller@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-12-04 14:43:32 +01:00
Johannes Berg
16bf948081 mac80211: remove sta_info.gtk_idx
This struct member is only assigned, never used otherwise;
remove it.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-07-17 15:37:54 +02:00
David S. Miller
3a07bd6fea Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/mellanox/mlx4/main.c
	net/packet/af_packet.c

Both conflicts were cases of simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-24 02:58:51 -07:00
Johannes Berg
51f458d961 mac80211: fix locking in update_vlan_tailroom_need_count()
Unfortunately, Michal's change to fix AP_VLAN crypto tailroom
caused a locking issue that was reported by lockdep, but only
in a few cases - the issue was a classic ABBA deadlock caused
by taking the mtx after the key_mtx, where normally they're
taken the other way around.

As the key mutex protects the field in question (I'm adding a
few annotations to make that clear) only the iteration needs
to be protected, but we can also iterate the interface list
with just RCU protection while holding the key mutex.

Fixes: f9dca80b98 ("mac80211: fix AP_VLAN crypto tailroom calculation")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-21 10:06:07 -07:00
Johannes Berg
30686bf7f5 mac80211: convert HW flags to unsigned long bitmap
As we're running out of hardware capability flags pretty quickly,
convert them to use the regular test_bit() style unsigned long
bitmaps.

This introduces a number of helper functions/macros to set and to
test the bits, along with new debugfs code.

The occurrences of an explicit __clear_bit() are intentional, the
drivers were never supposed to change their supported bits on the
fly. We should investigate changing this to be a per-frame flag.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-06-10 16:05:36 +02:00
Johannes Berg
206c59d1d7 Merge remote-tracking branch 'net-next/master' into mac80211-next
Merge back net-next to get wireless driver changes (from Kalle)
to be able to create the API change across all trees properly.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-06-10 12:45:09 +02:00
Johannes Berg
db388a567f mac80211: move TX PN to public part of key struct
For drivers supporting TSO or similar features, but that still have
PN assignment in software, there's a need to have some memory to
store the current PN value. As mac80211 already stores this and it's
somewhat complicated to add a per-driver area to the key struct (due
to the dynamic sizing thereof) it makes sense to just move the TX PN
to the keyconf, i.e. the public part of the key struct.

As TKIP is more complicated and we won't able to offload it in this
way right now (fast-xmit is skipped for TKIP unless the HW does it
all, and our hardware needs MMIC calculation in software) I've not
moved that for now - it's possible but requires exposing a lot of
the internal TKIP state.

As an bonus side effect, we can remove a lot of code by assuming the
keyseq struct has a certain layout - with BUILD_BUG_ON to verify it.

This might also improve performance, since now TX and RX no longer
share a cacheline.

Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-06-02 11:16:35 +02:00
David S. Miller
dda922c831 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/phy/amd-xgbe-phy.c
	drivers/net/wireless/iwlwifi/Kconfig
	include/net/mac80211.h

iwlwifi/Kconfig and mac80211.h were both trivial overlapping
changes.

The drivers/net/phy/amd-xgbe-phy.c file got removed in 'net-next' and
the bug fix that happened on the 'net' side is already integrated
into the rest of the amd-xgbe driver.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-01 22:51:30 -07:00
Michal Kazior
f9dca80b98 mac80211: fix AP_VLAN crypto tailroom calculation
Some splats I was seeing:

 (a) WARNING: CPU: 1 PID: 0 at /devel/src/linux/net/mac80211/wep.c:102 ieee80211_wep_add_iv
 (b) WARNING: CPU: 1 PID: 0 at /devel/src/linux/net/mac80211/wpa.c:73 ieee80211_tx_h_michael_mic_add
 (c) WARNING: CPU: 3 PID: 0 at /devel/src/linux/net/mac80211/wpa.c:433 ieee80211_crypto_ccmp_encrypt

I've seen (a) and (b) with ath9k hw crypto and (c)
with ath9k sw crypto. All of them were related to
insufficient skb tailroom and I was able to
trigger these with ping6 program.

AP_VLANs may inherit crypto keys from parent AP.
This wasn't considered and yielded problems in
some setups resulting in inability to transmit
data because mac80211 wouldn't resize skbs when
necessary and subsequently drop some packets due
to insufficient tailroom.

For efficiency purposes don't inspect both AP_VLAN
and AP sdata looking for tailroom counter. Instead
update AP_VLAN tailroom counters whenever their
master AP tailroom counter changes.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-05-20 15:10:11 +02:00
Johannes Berg
e3a55b5399 mac80211: validate cipher scheme PN length better
Currently, a cipher scheme can advertise an arbitrarily long
sequence counter, but mac80211 only supports up to 16 bytes
and the initial value from userspace will be truncated.

Fix two things:
 * don't allow the driver to register anything longer than
   the 16 bytes that mac80211 reserves space for
 * require userspace to specify a starting value with the
   correct length (or none at all)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-05-06 13:30:00 +02:00
Johannes Berg
a31cf1c69e mac80211: extend get_key() to return PN for all ciphers
For ciphers not supported by mac80211, the function currently
doesn't return any PN data. Fix this by extending the driver's
get_key_seq() a little more to allow moving arbitrary PN data.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-05-06 13:30:00 +02:00
Johannes Berg
17c18bf880 mac80211: add TX fastpath
In order to speed up mac80211's TX path, add the "fast-xmit" cache
that will cache the data frame 802.11 header and other data to be
able to build the frame more quickly. This cache is rebuilt when
external triggers imply changes, but a lot of the checks done per
packet today are simplified away to the check for the cache.

There's also a more detailed description in the code.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-04-22 10:02:25 +02:00
Cedric Izoard
c7ef38e0cc mac80211: Get IV len from key conf and not cipher scheme
When a key is installed using a cipher scheme, set a new
internal key flag (KEY_FLAG_CIPHER_SCHEME) on it, to allow
distinguishing such keys more easily.

In particular, use this flag on the TX path instead of
testing the sta->cipher_scheme pointer, as the station is
NULL for broad-/multicast message, and use the key's iv_len
instead of the cipher scheme information.

Signed-off-by: Cedric Izoard <cedric.izoard@ceva-dsp.com>
[add missing documentation, rewrite commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-03-17 12:34:26 +01:00
Jouni Malinen
8ade538bf3 mac80111: Add BIP-GMAC-128 and BIP-GMAC-256 ciphers
This allows mac80211 to configure BIP-GMAC-128 and BIP-GMAC-256 to the
driver and also use software-implementation within mac80211 when the
driver does not support this with hardware accelaration.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-01-27 11:10:13 +01:00
Jouni Malinen
56c52da2d5 mac80111: Add BIP-CMAC-256 cipher
This allows mac80211 to configure BIP-CMAC-256 to the driver and also
use software-implementation within mac80211 when the driver does not
support this with hardware accelaration.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-01-27 11:09:13 +01:00
Jouni Malinen
2b2ba0db1c mac80111: Add CCMP-256 cipher
This allows mac80211 to configure CCMP-256 to the driver and also use
software-implementation within mac80211 when the driver does not support
this with hardware accelaration.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
[squash ccmp256 -> mic_len argument change]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-01-27 11:07:35 +01:00
Jouni Malinen
00b9cfa3ff mac80111: Add GCMP and GCMP-256 ciphers
This allows mac80211 to configure GCMP and GCMP-256 to the driver and
also use software-implementation within mac80211 when the driver does
not support this with hardware accelaration.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
[remove a spurious newline]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-01-27 11:06:09 +01:00
Johannes Berg
fa7e1fbcb5 mac80211: allow drivers to control software crypto
Some drivers unfortunately cannot support software crypto, but
mac80211 currently assumes that they do.

This has the issue that if the hardware enabling fails for some
reason, the software fallback is used, which won't work. This
clearly isn't desirable, the error should be reported and the
key setting refused.

Support this in mac80211 by allowing drivers to set a new HW
flag IEEE80211_HW_SW_CRYPTO_CONTROL, in which case mac80211 will
only allow software fallback if the set_key() method returns 1.
The driver will also need to advertise supported cipher suites
so that mac80211 doesn't advertise any (future) software ciphers
that the driver can't actually do.

While at it, to make it easier to support this, refactor the
ieee80211_init_cipher_suites() code.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-01-22 22:01:01 +01:00
Ido Yariv
db12847ca8 mac80211: Re-fix accounting of the tailroom-needed counter
When hw acceleration is enabled, the GENERATE_IV or PUT_IV_SPACE flags
only require headroom space. Therefore, the tailroom-needed counter can
safely be decremented for most drivers.

The older incarnation of this patch (ca34e3b5) assumed that the above
holds true for all drivers. As reported by Christopher Chavez and
researched by Christian Lamparter and Larry Finger, this isn't a valid
assumption for p54 and cw1200.

Drivers that still require tailroom for ICV/MIC even when HW encryption
is enabled can use IEEE80211_KEY_FLAG_RESERVE_TAILROOM to indicate it.

Signed-off-by: Ido Yariv <idox.yariv@intel.com>
Cc: Christopher Chavez <chrischavez@gmx.us>
Cc: Christian Lamparter <chunkeey@googlemail.com>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Solomon Peachy <pizza@shaftnet.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-01-07 14:39:32 +01:00
Johannes Berg
1e359a5de8 Revert "mac80211: Fix accounting of the tailroom-needed counter"
This reverts commit ca34e3b5c8.

It turns out that the p54 and cw2100 drivers assume that there's
tailroom even when they don't say they really need it. However,
there's currently no way for them to explicitly say they do need
it, so for now revert this.

This fixes https://bugzilla.kernel.org/show_bug.cgi?id=90331.

Cc: stable@vger.kernel.org
Fixes: ca34e3b5c8 ("mac80211: Fix accounting of the tailroom-needed counter")
Reported-by: Christopher Chavez <chrischavez@gmx.us>
Bisected-by: Larry Finger <Larry.Finger@lwfinger.net>
Debugged-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2015-01-05 10:33:46 +01:00
Johannes Berg
28a9bc6812 mac80211: free management frame keys when removing station
When writing the code to allow per-station GTKs, I neglected to
take into account the management frame keys (index 4 and 5) when
freeing the station and only added code to free the first four
data frame keys.

Fix this by iterating the array of keys over the right length.

Cc: stable@vger.kernel.org
Fixes: e31b82136d ("cfg80211/mac80211: allow per-station GTKs")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2014-12-17 14:00:17 +01:00