linux/net/wireless
Johannes Berg 8bf862739a wext: fix message delay/ordering
Beniamino reported that he was getting an RTM_NEWLINK message for a
given interface, after the RTM_DELLINK for it. It turns out that the
message is a wireless extensions message, which was sent because the
interface had been connected and disconnection while it was deleted
caused a wext message.

For its netlink messages, wext uses RTM_NEWLINK, but the message is
without all the regular rtnetlink attributes, so "ip monitor link"
prints just rudimentary information:

5: wlan1: <BROADCAST,MULTICAST> mtu 1500 qdisc mq state DOWN group default
    link/ether 02:00:00:00:01:00 brd ff:ff:ff:ff:ff:ff
Deleted 5: wlan1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default
    link/ether 02:00:00:00:01:00 brd ff:ff:ff:ff:ff:ff
5: wlan1: <BROADCAST,MULTICAST,UP>
    link/ether
(from my hwsim reproduction)

This can cause userspace to get confused since it doesn't expect an
RTM_NEWLINK message after RTM_DELLINK.

The reason for this is that wext schedules a worker to send out the
messages, and the scheduling delay can cause the messages to get out
to userspace in different order.

To fix this, have wext register a netdevice notifier and flush out
any pending messages when netdevice state changes. This fixes any
ordering whenever the original message wasn't sent by a notifier
itself.

Cc: stable@vger.kernel.org
Reported-by: Beniamino Galvani <bgalvani@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2016-01-29 17:13:39 +01:00
..
.gitignore
ap.c cfg80211: export interface stopping function 2014-05-06 15:16:34 +02:00
chan.c cfg80211: use RTNL locked reg_can_beacon for IR-relaxation 2015-07-17 15:02:02 +02:00
core.c cfg80211: fix gHz to GHz 2015-10-15 16:17:07 +02:00
core.h cfg80211: Remove unused cfg80211_can_use_iftype_chan() 2015-12-04 14:43:32 +01:00
db.txt
debugfs.c mac80211: fix some snprintf misuses 2013-10-01 12:16:51 +02:00
debugfs.h
ethtool.c cfg80211: make ethtool the driver's responsibility 2014-06-23 11:05:33 +02:00
genregdb.awk wireless: fixup genregdb.awk for remove of antenna gain from wireless-regd 2014-07-21 12:24:20 +02:00
ibss.c Lots of updates for net-next; along with the usual flurry 2015-03-31 16:39:04 -04:00
Kconfig cfg80211: reg: make CRDA support optional 2015-10-16 09:15:39 +02:00
lib80211_crypt_ccmp.c lib80211: ratelimit key index mismatch 2015-12-04 14:43:32 +01:00
lib80211_crypt_tkip.c lib80211: ratelimit key index mismatch 2015-12-04 14:43:32 +01:00
lib80211_crypt_wep.c hostap: Don't use create_proc_read_entry() 2013-04-29 15:41:56 -04:00
lib80211.c lib80211: remove unused print_ssid() 2014-10-14 02:18:27 +02:00
Makefile cfg80211: 802.11p OCB mode handling 2014-11-04 13:18:17 +01:00
mesh.c cfg80211: export interface stopping function 2014-05-06 15:16:34 +02:00
mlme.c cfg80211: allow mgmt_frame_register callback to sleep 2015-07-17 15:38:26 +02:00
nl80211.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-12-17 22:08:28 -05:00
nl80211.h cfg80211: allow wiphy specific regdomain management 2014-12-17 11:49:55 +01:00
ocb.c cfg80211: ocb: Fix null pointer deref if join_ocb is unimplemented 2015-12-04 14:43:32 +01:00
radiotap.c radiotap: fix bitmap-end-finding buffer overrun 2013-12-16 12:06:43 +01:00
rdev-ops.h cfg80211: Add support for aborting an ongoing scan 2015-12-04 14:43:32 +01:00
reg.c regulatory: fix world regulatory domain data 2016-01-14 11:10:13 +01:00
reg.h cfg80211: Stop calling crda if it is not responsive 2015-04-01 11:22:38 +02:00
regdb.h cfg80211: relicense reg.c reg.h and genregdb.awk to ISC 2012-01-04 14:30:41 -05:00
scan.c cfg80211: Add multiple scan plans for scheduled scan 2015-10-13 10:35:26 +02:00
sme.c cfg80211: properly send NL80211_ATTR_DISCONNECTED_BY_AP in disconnect 2015-05-26 15:21:27 +02:00
sysfs.c cfg80211: Switch to PM ops 2015-05-20 15:00:12 +02:00
sysfs.h net: misc: Remove extern from function prototypes 2013-10-19 19:12:11 -04:00
trace.c cfg80211: add tracing to rdev-ops 2012-10-18 10:53:37 +02:00
trace.h cfg80211: Add support for aborting an ongoing scan 2015-12-04 14:43:32 +01:00
util.c cfg80211: Remove unused cfg80211_can_use_iftype_chan() 2015-12-04 14:43:32 +01:00
wext-compat.c cfg80211: wext: clear sinfo struct before calling driver 2015-06-09 13:54:58 -07:00
wext-compat.h cfg80211-wext: export symbols only when needed 2015-02-28 21:31:09 +01:00
wext-core.c wext: fix message delay/ordering 2016-01-29 17:13:39 +01:00
wext-priv.c wext: fix potential private ioctl memory content leak 2010-09-20 13:41:40 -04:00
wext-proc.c net: proc: change proc_net_remove to remove_proc_entry 2013-02-18 14:53:08 -05:00
wext-sme.c wireless: Use eth_<foo>_addr instead of memset 2015-03-03 17:01:38 -05:00
wext-spy.c wireless: Convert compare_ether_addr to ether_addr_equal 2012-05-09 20:49:19 -04:00