[PATCH] iwlwifi: add missing rcu_read_lock

[PATCH] iwlwifi: add missing rcu_read_lock

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

Using ieee80211_find_sta() needs to be under
RCU read lock, which iwlwifi currently misses,
so fix it.

Cc: stable@kernel.org
Reported-by: Miles Lane <miles.lane@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 drivers/net/wireless/iwlwifi/iwl-agn-tx.c |    2 ++
 1 file changed, 2 insertions(+)

--- wireless-testing.orig/drivers/net/wireless/iwlwifi/iwl-agn-tx.c	2010-06-07 21:17:56.000000000 +0200
+++ wireless-testing/drivers/net/wireless/iwlwifi/iwl-agn-tx.c	2010-06-07 21:18:04.000000000 +0200
@@ -1146,6 +1146,7 @@ static void iwlagn_tx_status(struct iwl_
 	struct ieee80211_sta *sta;
 	struct iwl_station_priv *sta_priv;
 
+	rcu_read_lock();
 	sta = ieee80211_find_sta(priv->vif, hdr->addr1);
 	if (sta) {
 		sta_priv = (void *)sta->drv_priv;
@@ -1154,6 +1155,7 @@ static void iwlagn_tx_status(struct iwl_
 		    atomic_dec_return(&sta_priv->pending_frames) == 0)
 			ieee80211_sta_block_awake(priv->hw, sta, false);
 	}
+	rcu_read_unlock();
 
 	ieee80211_tx_status_irqsafe(priv->hw, skb);
 }

Re: [PATCH] iwlwifi: add missing rcu_read_lock

[Miles Lane]

On Mon, Jun 7, 2010 at 3:20 PM, Johannes Berg <johannes@sipsolutions.net> wrote:
> From: Johannes Berg <johannes.berg@intel.com>
>
> Using ieee80211_find_sta() needs to be under
> RCU read lock, which iwlwifi currently misses,
> so fix it.
>
> Cc: stable@kernel.org
> Reported-by: Miles Lane <miles.lane@gmail.com>
> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
> ---
>  drivers/net/wireless/iwlwifi/iwl-agn-tx.c |    2 ++
>  1 file changed, 2 insertions(+)
>
> --- wireless-testing.orig/drivers/net/wireless/iwlwifi/iwl-agn-tx.c     2010-06-07 21:17:56.000000000 +0200
> +++ wireless-testing/drivers/net/wireless/iwlwifi/iwl-agn-tx.c  2010-06-07 21:18:04.000000000 +0200
> @@ -1146,6 +1146,7 @@ static void iwlagn_tx_status(struct iwl_
>        struct ieee80211_sta *sta;
>        struct iwl_station_priv *sta_priv;
>
> +       rcu_read_lock();
>        sta = ieee80211_find_sta(priv->vif, hdr->addr1);
>        if (sta) {
>                sta_priv = (void *)sta->drv_priv;
> @@ -1154,6 +1155,7 @@ static void iwlagn_tx_status(struct iwl_
>                    atomic_dec_return(&sta_priv->pending_frames) == 0)
>                        ieee80211_sta_block_awake(priv->hw, sta, false);
>        }
> +       rcu_read_unlock();
>
>        ieee80211_tx_status_irqsafe(priv->hw, skb);
>  }
>
>
>

Unclean patch application - is this to be expected?

patching file drivers/net/wireless/iwlwifi/iwl-agn-tx.c
Hunk #1 succeeded at 1125 (offset -21 lines).
Hunk #2 succeeded at 1134 (offset -21 lines).

Re: [PATCH] iwlwifi: add missing rcu_read_lock

[reinette chatre]

On Mon, 2010-06-07 at 12:20 -0700, Johannes Berg wrote:
> From: Johannes Berg <johannes.berg@intel.com>
> 
> Using ieee80211_find_sta() needs to be under
> RCU read lock, which iwlwifi currently misses,
> so fix it.
> 
> Cc: stable@kernel.org
> Reported-by: Miles Lane <miles.lane@gmail.com>
> Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Acked-by: Reinette Chatre <reinette.chatre@intel.com>

Reinette

Re: [PATCH] iwlwifi: add missing rcu_read_lock

[Miles Lane]

Tested.  Looks good.

On Mon, Jun 7, 2010 at 5:34 PM, reinette chatre
<reinette.chatre@intel.com> wrote:
> On Mon, 2010-06-07 at 12:20 -0700, Johannes Berg wrote:
>> From: Johannes Berg <johannes.berg@intel.com>
>>
>> Using ieee80211_find_sta() needs to be under
>> RCU read lock, which iwlwifi currently misses,
>> so fix it.
>>
>> Cc: stable@kernel.org
>> Reported-by: Miles Lane <miles.lane@gmail.com>
>> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
>
> Acked-by: Reinette Chatre <reinette.chatre@intel.com>
>
> Reinette
>
>
>

Re: [PATCH] iwlwifi: add missing rcu_read_lock

[Johannes Berg]

On Mon, 2010-06-07 at 17:31 -0400, Miles Lane wrote:

> > --- wireless-testing.orig/drivers/net/wireless/iwlwifi/iwl-agn-tx.c     2010-06-07 21:17:56.000000000 +0200
> > +++ wireless-testing/drivers/net/wireless/iwlwifi/iwl-agn-tx.c  2010-06-07 21:18:04.000000000 +0200
> > @@ -1146,6 +1146,7 @@ static void iwlagn_tx_status(struct iwl_
> >        struct ieee80211_sta *sta;
> >        struct iwl_station_priv *sta_priv;
> >
> > +       rcu_read_lock();
> >        sta = ieee80211_find_sta(priv->vif, hdr->addr1);
> >        if (sta) {
> >                sta_priv = (void *)sta->drv_priv;
> > @@ -1154,6 +1155,7 @@ static void iwlagn_tx_status(struct iwl_
> >                    atomic_dec_return(&sta_priv->pending_frames) == 0)
> >                        ieee80211_sta_block_awake(priv->hw, sta, false);
> >        }
> > +       rcu_read_unlock();
> >
> >        ieee80211_tx_status_irqsafe(priv->hw, skb);
> >  }
> >
> >
> >
> 
> Unclean patch application - is this to be expected?
> 
> patching file drivers/net/wireless/iwlwifi/iwl-agn-tx.c
> Hunk #1 succeeded at 1125 (offset -21 lines).
> Hunk #2 succeeded at 1134 (offset -21 lines).

Didn't pay much attention what tree I generated it against since I knew
this code hasn't changed in a while ... so the offset looks perfectly
fine. Fuzz I'd have been surprised about :)

johannes