tree 9e246a1aa36afcd735940a07253124b138e0ed03
parent d1d8f44a4e3c730984283c0bf4b3458e3a88c15a
author Pavel Emelyanov <xemul@openvz.org> 1208936835 +0400
committer John W. Linville <linville@tuxdriver.com> 1209000335 -0400

mac80211: Fix race between ieee80211_rx_bss_put and lookup routines.

The put routine first decrements the users counter and then
(if it is zero) locks the sta_bss_lock and removes one from
the list and the hash.

Thus, any of ieee80211_sta_config_auth, ieee80211_rx_bss_get
or ieee80211_rx_mesh_bss_get can race with it by finding a
bss that is about to get kfree-ed.

Using atomic_dec_and_lock in ieee80211_rx_bss_put takes care
of this race.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>