[PATCH 4/5] mwl8k: prevent crash in ->configure_filter() if no interface was added

[PATCH 4/5] mwl8k: prevent crash in ->configure_filter() if no interface was added

[Lennert Buytenhek]

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Acked-by: Nicolas Pitre <nico@marvell.com>
---
 drivers/net/wireless/mwl8k.c |   12 ++++++++----
 1 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/mwl8k.c b/drivers/net/wireless/mwl8k.c
index a92752e..4890f8f 100644
--- a/drivers/net/wireless/mwl8k.c
+++ b/drivers/net/wireless/mwl8k.c
@@ -261,7 +261,7 @@ struct mwl8k_vif {
 	 */
 };
 
-#define MWL8K_VIF(_vif) (struct mwl8k_vif *)(&((_vif)->drv_priv))
+#define MWL8K_VIF(_vif) ((struct mwl8k_vif *)&((_vif)->drv_priv))
 
 static const struct ieee80211_channel mwl8k_channels[] = {
 	{ .center_freq = 2412, .hw_value = 1, },
@@ -3228,15 +3228,19 @@ static int mwl8k_configure_filter_wt(struct work_struct *wt)
 	struct dev_addr_list *mclist = worker->mclist;
 
 	struct mwl8k_priv *priv = hw->priv;
-	struct mwl8k_vif *mv_vif;
 	int rc = 0;
 
 	if (changed_flags & FIF_BCN_PRBRESP_PROMISC) {
 		if (*total_flags & FIF_BCN_PRBRESP_PROMISC)
 			rc = mwl8k_cmd_set_pre_scan(hw);
 		else {
-			mv_vif = MWL8K_VIF(priv->vif);
-			rc = mwl8k_cmd_set_post_scan(hw, mv_vif->bssid);
+			u8 *bssid;
+
+			bssid = "\x00\x00\x00\x00\x00\x00";
+			if (priv->vif != NULL)
+				bssid = MWL8K_VIF(priv->vif)->bssid;
+
+			rc = mwl8k_cmd_set_post_scan(hw, bssid);
 		}
 	}
 
-- 
1.5.6.4

Re: [PATCH 4/5] mwl8k: prevent crash in ->configure_filter() if no interface was added

[Johannes Berg]

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On Mon, 2009-08-03 at 21:58 +0200, Lennert Buytenhek wrote:

>  	if (changed_flags & FIF_BCN_PRBRESP_PROMISC) {
>  		if (*total_flags & FIF_BCN_PRBRESP_PROMISC)
>  			rc = mwl8k_cmd_set_pre_scan(hw);
>  		else {
> -			mv_vif = MWL8K_VIF(priv->vif);
> -			rc = mwl8k_cmd_set_post_scan(hw, mv_vif->bssid);

Btw, there are pre- and post-scan hooks now.

johannes

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Re: [PATCH 4/5] mwl8k: prevent crash in ->configure_filter() if no interface was added

[Lennert Buytenhek]

On Mon, Aug 03, 2009 at 10:03:10PM +0200, Johannes Berg wrote:

> >  	if (changed_flags & FIF_BCN_PRBRESP_PROMISC) {
> >  		if (*total_flags & FIF_BCN_PRBRESP_PROMISC)
> >  			rc = mwl8k_cmd_set_pre_scan(hw);
> >  		else {
> > -			mv_vif = MWL8K_VIF(priv->vif);
> > -			rc = mwl8k_cmd_set_post_scan(hw, mv_vif->bssid);
> 
> Btw, there are pre- and post-scan hooks now.

These hardware commands are slightly misnamed -- they are called
PRE_SCAN/POST_SCAN, but what they do is program the receive filter.
It seems appropriate to keep that in ->configure_filter() ?

Re: [PATCH 4/5] mwl8k: prevent crash in ->configure_filter() if no interface was added

[Johannes Berg]

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On Tue, 2009-08-04 at 01:46 +0200, Lennert Buytenhek wrote:
> On Mon, Aug 03, 2009 at 10:03:10PM +0200, Johannes Berg wrote:
> 
> > >  	if (changed_flags & FIF_BCN_PRBRESP_PROMISC) {
> > >  		if (*total_flags & FIF_BCN_PRBRESP_PROMISC)
> > >  			rc = mwl8k_cmd_set_pre_scan(hw);
> > >  		else {
> > > -			mv_vif = MWL8K_VIF(priv->vif);
> > > -			rc = mwl8k_cmd_set_post_scan(hw, mv_vif->bssid);
> > 
> > Btw, there are pre- and post-scan hooks now.
> 
> These hardware commands are slightly misnamed -- they are called
> PRE_SCAN/POST_SCAN, but what they do is program the receive filter.
> It seems appropriate to keep that in ->configure_filter() ?

I guess it depends how they configure the filter. :)
If they really do the beacon/probe response filter thing then yes. For
b43, for instance, they also disable CFP updates etc. so aren't just
that. And you can get FIF_BCN_PRBRESP_PROMISC even while _not_ scanning,
due to monitor interfaces, so it really depends what they do (no CFP
disabling wanted then).

johannes

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