Skip to content
  1. Apr 04, 2015
  3. Apr 03, 2015
  5. Apr 02, 2015
  7. Apr 01, 2015
    • Johannes Berg's avatar
      mac80211: fix RX A-MPDU session reorder timer deletion · 788211d8
      Johannes Berg authored 
      

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.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
      788211d8
    • Stefan Lippers-Hollmann's avatar
      x86/reboot: Add ASRock Q1900DC-ITX mainboard reboot quirk · 80313b30
      Stefan Lippers-Hollmann authored 
      

The ASRock Q1900DC-ITX mainboard (Baytrail-D) hangs randomly in
both BIOS and UEFI mode while rebooting unless reboot=pci is
used. Add a quirk to reboot via the pci method.

The problem is very intermittent and hard to debug, it might succeed
rebooting just fine 40 times in a row - but fails half a dozen times
the next day. It seems to be slightly less common in BIOS CSM mode
than native UEFI (with the CSM disabled), but it does happen in either
mode. Since I've started testing this patch in late january, rebooting
has been 100% reliable.

Most of the time it already hangs during POST, but occasionally it
might even make it through the bootloader and the kernel might even
start booting, but then hangs before the mode switch. The same symptoms
occur with grub-efi, gummiboot and grub-pc, just as well as (at least)
kernel 3.16-3.19 and 4.0-rc6 (I haven't tried older kernels than 3.16).
Upgrading to the most current mainboard firmware of the ASRock
Q1900DC-ITX, version 1.20, does not improve the situation.

( Searching the web seems to suggest that other Bay Trail-D mainboards
  might be affected as well. )
--
Signed-off-by: default avatarStefan Lippers-Hollmann <s.l-h@gmx.de>
Cc: <stable@vger.kernel.org>
Cc: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/20150330224427.0fb58e42@mir


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      80313b30
    • Steve French's avatar
      Fix warning · 4c5930e8
      Steve French authored 
      

Coverity reports a warning due to unitialized attr structure in one
code path.

Reported by Coverity (CID 728535)

Signed-off-by: default avatarSteve French <smfrench@gmail.com>
Reviewed-by: default avatarJeff Layton <jlayton@samba.org>
      4c5930e8
    • Steve French's avatar
      Fix another dereference before null check warning · dfebe400
      Steve French authored 
      

null tcon is not possible in these paths so
remove confusing null check

Reported by Coverity (CID 728519)

Signed-off-by: default avatarSteve French <smfrench@gmail.com>
Reviewed-by: default avatarJeff Layton <jlayton@samba.org>
      dfebe400