redonkable/alistair23-linux
redonkable/alistair23-linux
1
0
Fork 0
Code Releases Activity

mac80211: safely free beacon in ieee80211_if_reinit

Browse source 
If ieee80211_if_reinit() is called from ieee80211_unregister_hw()
then it is possible that the driver will still request a beacon
(it is allowed to until ieee80211_unregister_hw() has returned.)
This means we need to use an RCU-protected write to the beacon
information even in this function.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Johannes Berg 2008-02-25 16:27:42 +01:00 committed by John W. Linville
parent 2485f7105f
commit e6a5ddf208
1 changed files with 5 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
net/mac80211/ieee80211_iface.c
View file

@ -193,6 +193,7 @@ void ieee80211_if_reinit(struct net_device *dev)
/* Remove all virtual interfaces that use this BSS /* Remove all virtual interfaces that use this BSS
* as their sdata->bss */ * as their sdata->bss */
struct ieee80211_sub_if_data *tsdata, *n; struct ieee80211_sub_if_data *tsdata, *n;
struct beacon_data *beacon;
list_for_each_entry_safe(tsdata, n, &local->interfaces, list) { list_for_each_entry_safe(tsdata, n, &local->interfaces, list) {
if (tsdata != sdata && tsdata->bss == &sdata->u.ap) { if (tsdata != sdata && tsdata->bss == &sdata->u.ap) {
@ -210,7 +211,10 @@ void ieee80211_if_reinit(struct net_device *dev)
} }
} }
kfree(sdata->u.ap.beacon); beacon = sdata->u.ap.beacon;
rcu_assign_pointer(sdata->u.ap.beacon, NULL);
synchronize_rcu();
kfree(beacon);
while ((skb = skb_dequeue(&sdata->u.ap.ps_bc_buf))) { while ((skb = skb_dequeue(&sdata->u.ap.ps_bc_buf))) {
local->total_ps_buffered--; local->total_ps_buffered--;