From 685429623f88d84f98bd5daffc3c427c408740d4 Mon Sep 17 00:00:00 2001 From: Juuso Oikarinen Date: Wed, 9 Jun 2010 13:43:26 +0300 Subject: mac80211: Fix circular locking dependency in ARP filter handling There is a circular locking dependency when configuring the hardware ARP filters on association, occurring when flushing the mac80211 workqueue. This is what happens: [ 92.026800] ======================================================= [ 92.030507] [ INFO: possible circular locking dependency detected ] [ 92.030507] 2.6.34-04781-g2b2c009 #85 [ 92.030507] ------------------------------------------------------- [ 92.030507] modprobe/5225 is trying to acquire lock: [ 92.030507] ((wiphy_name(local->hw.wiphy))){+.+.+.}, at: [] flush_workq ueue+0x0/0xb0 [ 92.030507] [ 92.030507] but task is already holding lock: [ 92.030507] (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x12/0x20 [ 92.030507] [ 92.030507] which lock already depends on the new lock. [ 92.030507] [ 92.030507] [ 92.030507] the existing dependency chain (in reverse order) is: [ 92.030507] [ 92.030507] -> #2 (rtnl_mutex){+.+.+.}: [ 92.030507] [] lock_acquire+0xdb/0x110 [ 92.030507] [] mutex_lock_nested+0x44/0x300 [ 92.030507] [] rtnl_lock+0x12/0x20 [ 92.030507] [] ieee80211_assoc_done+0x6c/0xe0 [mac80211] [ 92.030507] [] ieee80211_work_work+0x31d/0x1280 [mac80211] [ 92.030507] -> #1 ((&local->work_work)){+.+.+.}: [ 92.030507] [] lock_acquire+0xdb/0x110 [ 92.030507] [] worker_thread+0x22a/0x370 [ 92.030507] [] kthread+0x96/0xb0 [ 92.030507] [] kernel_thread_helper+0x4/0x10 [ 92.030507] [ 92.030507] -> #0 ((wiphy_name(local->hw.wiphy))){+.+.+.}: [ 92.030507] [] __lock_acquire+0x1c0c/0x1d50 [ 92.030507] [] lock_acquire+0xdb/0x110 [ 92.030507] [] flush_workqueue+0x4e/0xb0 [ 92.030507] [] ieee80211_stop_device+0x2b/0xb0 [mac80211] [ 92.030507] [] ieee80211_stop+0x3e5/0x680 [mac80211] The locking in this case is quite complex. Fix the problem by rewriting the way the hardware ARP filter list is handled - i.e. make a copy of the address list to the bss_conf struct, and provide that list to the hardware driver when needed. The current patch will enable filtering also in promiscuous mode. This may need to be changed in the future. Reported-by: Reinette Chatre Signed-off-by: Juuso Oikarinen Signed-off-by: John W. Linville --- net/mac80211/ieee80211_i.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net/mac80211/ieee80211_i.h') diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index c3c2be3f8a2c..9b3c3f971d28 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -514,6 +514,8 @@ struct ieee80211_sub_if_data { struct work_struct work; struct sk_buff_head skb_queue; + bool arp_filter_state; + /* * AP this belongs to: self in AP mode and * corresponding AP in VLAN mode, NULL for -- cgit v1.2.3