linux/net
Johannes Berg 3bdb2d48c5 cfg80211: fix race between deauth and assoc response
Joseph Nahmias reported, in http://bugs.debian.org/562016,
that he was getting the following warning (with some log
around the issue):

  ath0: direct probe to AP 00:11:95:77:e0:b0 (try 1)
  ath0: direct probe responded
  ath0: authenticate with AP 00:11:95:77:e0:b0 (try 1)
  ath0: authenticated
  ath0: associate with AP 00:11:95:77:e0:b0 (try 1)
  ath0: deauthenticating from 00:11:95:77:e0:b0 by local choice (reason=3)
  ath0: direct probe to AP 00:11:95:77:e0:b0 (try 1)
  ath0: RX AssocResp from 00:11:95:77:e0:b0 (capab=0x421 status=0 aid=2)
  ath0: associated
  ------------[ cut here ]------------
  WARNING: at net/wireless/mlme.c:97 cfg80211_send_rx_assoc+0x14d/0x152 [cfg80211]()
  Hardware name: 7658CTO
  ...
  Pid: 761, comm: phy0 Not tainted 2.6.32-trunk-686 #1
  Call Trace:
   [<c1030a5d>] ? warn_slowpath_common+0x5e/0x8a
   [<c1030a93>] ? warn_slowpath_null+0xa/0xc
   [<f86cafc7>] ? cfg80211_send_rx_assoc+0x14d/0x152
  ...
  ath0: link becomes ready
  ath0: deauthenticating from 00:11:95:77:e0:b0 by local choice (reason=3)
  ath0: no IPv6 routers present
  ath0: link is not ready
  ath0: direct probe to AP 00:11:95:77:e0:b0 (try 1)
  ath0: direct probe responded
  ath0: authenticate with AP 00:11:95:77:e0:b0 (try 1)
  ath0: authenticated
  ath0: associate with AP 00:11:95:77:e0:b0 (try 1)
  ath0: RX ReassocResp from 00:11:95:77:e0:b0 (capab=0x421 status=0 aid=2)
  ath0: associated

It is not clear to me how the first "direct probe" here
happens, but this seems to be a race condition, if the
user requests to deauth after requesting assoc, but before
the assoc response is received. In that case, it may
happen that mac80211 tries to report the assoc success to
cfg80211, but gets blocked on the wdev lock that is held
because the user is requesting the deauth.

The result is that we run into a warning. This is mostly
harmless, but maybe cause an unexpected event to be sent
to userspace; we'd send an assoc success event although
userspace was no longer expecting that.

To fix this, remove the warning and check whether the
race happened and in that case abort processing.

Reported-by: Joseph Nahmias <joe@nahmias.net>
Cc: stable@kernel.org
Cc: 562016-quiet@bugs.debian.org
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-12-28 16:19:54 -05:00
..
9p net: Move && and || to end of previous line 2009-11-29 16:55:45 -08:00
802 sysctl net: Remove unused binary sysctl code 2009-11-12 02:05:06 -08:00
8021q netdevice: provide common routine for macvlan and vlan operstate management 2009-12-03 15:59:22 -08:00
appletalk Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
atm atm: [br2684] allow routed mode operation again 2009-12-08 20:22:31 -08:00
ax25 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
bluetooth Bluetooth: Add RFCOMM option to use L2CAP ERTM mode 2009-12-03 19:34:26 +01:00
bridge Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
can net: Move && and || to end of previous line 2009-11-29 16:55:45 -08:00
core Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
dcb net: Move && and || to end of previous line 2009-11-29 16:55:45 -08:00
dccp tcp: Fix a connect() race with timewait sockets 2009-12-08 20:17:51 -08:00
decnet Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
dsa netdev: convert pseudo-devices to netdev_tx_t 2009-09-01 01:13:07 -07:00
econet net: use net_eq to compare nets 2009-11-25 15:14:13 -08:00
ethernet remove deprecated and not used: print_mac() 2009-11-15 22:21:34 -08:00
ieee802154 net: use net_eq to compare nets 2009-11-25 15:14:13 -08:00
ipv4 tcp: fix retrans_stamp advancing in error cases 2009-12-08 20:56:12 -08:00
ipv6 tcp: Fix a connect() race with timewait sockets 2009-12-08 20:17:51 -08:00
ipx Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
irda Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
iucv iucv: add work_queue cleanup for suspend 2009-11-13 20:46:58 -08:00
key net: Simplify af_key pernet operations. 2009-12-01 16:15:54 -08:00
lapb net: remove NET_RX_BAD and NET_RX_CN* defines 2009-07-05 19:15:35 -07:00
llc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
mac80211 mac80211: fix ibss join with fixed-bssid 2009-12-28 15:56:35 -05:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
netlabel net: rename skb->iif to skb->skb_iif 2009-11-20 15:35:04 -08:00
netlink net: use net_eq to compare nets 2009-11-25 15:14:13 -08:00
netrom Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
packet net: Move && and || to end of previous line 2009-11-29 16:55:45 -08:00
phonet Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
rds Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
rfkill net/rfkill/core.c: work around gcc-4.0.2 silliness 2009-12-07 16:51:23 -05:00
rose Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
rxrpc net: use net_eq to compare nets 2009-11-25 15:14:13 -08:00
sched net: Move && and || to end of previous line 2009-11-29 16:55:45 -08:00
sctp sctp: fix compile error due to sysctl mismerge 2009-12-08 12:51:22 -08:00
sunrpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
tipc net: Move && and || to end of previous line 2009-11-29 16:55:45 -08:00
unix Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
wanrouter headers: smp_lock.h redux 2009-07-12 12:22:34 -07:00
wimax net: Move && and || to end of previous line 2009-11-29 16:55:45 -08:00
wireless cfg80211: fix race between deauth and assoc response 2009-12-28 16:19:54 -05:00
x25 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
xfrm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
compat.c net: compat_sys_recvmmsg user timespec arg can be NULL 2009-12-02 01:23:23 -08:00
Kconfig net/compat/wext: send different messages to compat tasks 2009-07-15 08:53:39 -07:00
Makefile net: remove redundant sched/ in net/Makefile 2009-07-12 20:11:14 -07:00
nonet.c
socket.c net: compat_mmsghdr must be used in sys_recvmmsg 2009-12-02 01:23:23 -08:00
sysctl_net.c net: sysctl_net - use net_eq to compare nets 2009-03-16 16:23:30 +01:00
TUNABLE