linux.git/net/mac80211, branch v2.6.32

mac80211: fix spurious delBA handling

2009-11-30T18:55:51+00:00

Lennert Buytenhek noticed that delBA handling in mac80211
was broken and has remotely triggerable problems, some of
which are due to some code shuffling I did that ended up
changing the order in which things were done -- this was

  commit d75636ef9c1af224f1097941879d5a8db7cd04e5
  Author: Johannes Berg 
  Date:   Tue Feb 10 21:25:53 2009 +0100

    mac80211: RX aggregation: clean up stop session

and other parts were already present in the original

  commit d92684e66091c0f0101819619b315b4bb8b5bcc5
  Author: Ron Rindjunsky 
  Date:   Mon Jan 28 14:07:22 2008 +0200

      mac80211: A-MPDU Tx add delBA from recipient support

The first problem is that I moved a BUG_ON before various
checks -- thereby making it possible to hit. As the comment
indicates, the BUG_ON can be removed since the ampdu_action
callback must already exist when the state is != IDLE.

The second problem isn't easily exploitable but there's a
race condition due to unconditionally setting the state to
OPERATIONAL when a delBA frame is received, even when no
aggregation session was ever initiated. All the drivers
accept stopping the session even then, but that opens a
race window where crashes could happen before the driver
accepts it. Right now, a WARN_ON may happen with non-HT
drivers, while the race opens only for HT drivers.

For this case, there are two things necessary to fix it:
 1) don't process spurious delBA frames, and be more careful
    about the session state; don't drop the lock

 2) HT drivers need to be prepared to handle a session stop
    even before the session was really started -- this is
    true for all drivers (that support aggregation) but
    iwlwifi which can be fixed easily. The other HT drivers
    (ath9k and ar9170) are behaving properly already.

Reported-by: Lennert Buytenhek 
Cc: stable@kernel.org
Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

mac80211: fix two remote exploits

2009-11-30T18:52:21+00:00

Lennert Buytenhek noticed a remotely triggerable problem
in mac80211, which is due to some code shuffling I did
that ended up changing the order in which things were
done -- this was in

  commit d75636ef9c1af224f1097941879d5a8db7cd04e5
  Author: Johannes Berg 
  Date:   Tue Feb 10 21:25:53 2009 +0100

    mac80211: RX aggregation: clean up stop session

The problem is that the BUG_ON moved before the various
checks, and as such can be triggered.

As the comment indicates, the BUG_ON can be removed since
the ampdu_action callback must already exist when the
state is OPERATIONAL.

A similar code path leads to a WARN_ON in
ieee80211_stop_tx_ba_session, which can also be removed.

Cc: stable@kernel.org [2.6.29+]
Cc: Lennert Buytenhek 
Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6

2009-11-23T22:01:47+00:00

mac80211: fix resume

2009-11-19T16:08:39+00:00

When mac80211 resumes, it currently first sets suspended
to false so the driver can start doing things and we can
receive frames.

However, if we actually receive frames then it can end
up starting some work which adds timers and then later
runs into a BUG_ON in the timer code because it tries
add_timer() on a pending timer.

Fix this by keeping track of the resuming process by
introducing a new variable 'resuming' which gets set to
true early on instead of setting 'suspended' to false,
and allow queueing work but not receiving frames while
resuming.

Reported-by: Maxim Levitsky 
Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

mac80211: fix addba timer (again...)

2009-11-18T22:01:47+00:00

commit 2171abc58644e09dbba546d91366b12743115396
  Author: Johannes Berg 
  Date:   Thu Oct 29 08:34:00 2009 +0100

      mac80211: fix addba timer

left a problem in there, even if the timer was
never started it could be deleted and then added.

Linus pointed out that del_timer_sync() isn't
actually needed if we make the timer able to
deal with no longer being needed when it gets
queued _while_ we're in the locked section that
also deletes it. For that the timer function only
needs to check the HT_ADDBA_RECEIVED_MSK bit as
well as the HT_ADDBA_REQUESTED_MSK bit, only if
the former is clear should it do anything.

Cc: Linus Torvalds 
Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6

2009-11-03T15:44:01+00:00

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (21 commits)
  mac80211: check interface is down before type change
  cfg80211: fix NULL ptr deref
  libertas if_usb: Fix crash on 64-bit machines
  mac80211: fix reason code output endianness
  mac80211: fix addba timer
  ath9k: fix misplaced semicolon on rate control
  b43: Fix DMA TX bounce buffer copying
  mac80211: fix BSS leak
  rt73usb.c : more ids
  ipw2200: fix oops on missing firmware
  gre: Fix dev_addr clobbering for gretap
  sky2: set carrier off in probe
  net: fix sk_forward_alloc corruption
  pcnet_cs: add cis of PreMax PE-200 ethernet pcmcia card
  r8169: Fix card drop incoming VLAN tagged MTU byte large jumbo frames
  ibmtr: possible Read buffer overflow?
  net: Fix RPF to work with policy routing
  net: fix kmemcheck annotations
  e1000e: rework disable K1 at 1000Mbps for 82577/82578
  e1000e: config PHY via software after resets
  ...

mac80211: check interface is down before type change

2009-11-02T20:14:07+00:00

For some strange reason the netif_running() check
ended up after the actual type change instead of
before, potentially causing all kinds of problems
if the interface is up while changing the type;
one of the problems manifests itself as a warning:

WARNING: at net/mac80211/iface.c:651 ieee80211_teardown_sdata+0xda/0x1a0 [mac80211]()
Hardware name: Aspire one
Pid: 2596, comm: wpa_supplicant Tainted: G        W  2.6.31-10-generic #32-Ubuntu
Call Trace:
 [] warn_slowpath_common+0x6d/0xa0
 [] warn_slowpath_null+0x15/0x20
 [] ieee80211_teardown_sdata+0xda/0x1a0 [mac80211]
 [] ieee80211_if_change_type+0x4a/0xc0 [mac80211]
 [] ieee80211_change_iface+0x61/0xa0 [mac80211]
 [] cfg80211_wext_siwmode+0xc7/0x120 [cfg80211]
 [] ioctl_standard_call+0x58/0xf0

(http://www.kerneloops.org/searchweek.php?search=ieee80211_teardown_sdata)

Cc: Arjan van de Ven 
Cc: stable@kernel.org
Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

mac80211: fix reason code output endianness

2009-10-30T19:50:25+00:00

When HT debugging is enabled and we receive a DelBA
frame we print out the reason code in the wrong byte
order. Fix that so we don't get weird values printed.

Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

mac80211: fix addba timer

2009-10-30T19:50:25+00:00

The addba timer function acquires the sta spinlock,
but at the same time we try to del_timer_sync() it
under the spinlock which can produce deadlocks.

To fix this, always del_timer_sync() the timer in
ieee80211_process_addba_resp() and add it again
after checking the conditions, if necessary.

Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

mac80211: fix BSS leak

2009-10-30T19:50:24+00:00

The IBSS code leaks a BSS struct after telling
cfg80211 about a given BSS by passing a frame.

Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville