2006-12-03 07:42:08

by Maxime Austruy

Subject: [PATCH] softmac: fix unbalanced mutex_lock/unlock in ieee80211softmac_wx_set_mlme

Found a hang while playing with wpa_supplicant and a zd1211 usb adapter
using linux 2.6.19. The problem is that ieee80211softmac_wx_set_mlme
forgets to release a mutex when mlme->cmd is IW_MLME_DEAUTH. The fix
below allows me to kill wpa_supplicant and to restart it without having
to reboot the machine. FWIW, it seems that the problem was introduced
between 2.6.19-rc2 and 2.6.19-rc3 when this function was changed to use
a mutex.

Signed-off-by: Maxime Austruy <[email protected]>

--
net/ieee80211/softmac/ieee80211softmac_wx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- linux.orig/net/ieee80211/softmac/ieee80211softmac_wx.c 2006-11-29 13:57:37.000000000 -0800
+++ linux/net/ieee80211/softmac/ieee80211softmac_wx.c 2006-12-02 22:58:20.000000000 -0800
@@ -495,7 +495,8 @@ ieee80211softmac_wx_set_mlme(struct net_
printk(KERN_DEBUG PFX "wx_set_mlme: we should know the net here...\n");
goto out;
}
- return ieee80211softmac_deauth_req(mac, net, reason);
+ err = ieee80211softmac_deauth_req(mac, net, reason);
+ goto out;
case IW_MLME_DISASSOC:
ieee80211softmac_send_disassoc_req(mac, reason);
mac->associnfo.associated = 0;

2006-12-03 16:23:36

by Larry Finger

Subject: Re: [PATCH] softmac: fix unbalanced mutex_lock/unlock in ieee80211softmac_wx_set_mlme

Maxime Austruy wrote:
> Found a hang while playing with wpa_supplicant and a zd1211 usb adapter
> using linux 2.6.19. The problem is that ieee80211softmac_wx_set_mlme
> forgets to release a mutex when mlme->cmd is IW_MLME_DEAUTH. The fix
> below allows me to kill wpa_supplicant and to restart it without having
> to reboot the machine. FWIW, it seems that the problem was introduced
> between 2.6.19-rc2 and 2.6.19-rc3 when this function was changed to use
> a mutex.
>
> Signed-off-by: Maxime Austruy <[email protected]>
Signed-off-by: Larry Finger <[email protected]>
>
> --
> net/ieee80211/softmac/ieee80211softmac_wx.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> --- linux.orig/net/ieee80211/softmac/ieee80211softmac_wx.c 2006-11-29 13:57:37.000000000 -0800
> +++ linux/net/ieee80211/softmac/ieee80211softmac_wx.c 2006-12-02 22:58:20.000000000 -0800
> @@ -495,7 +495,8 @@ ieee80211softmac_wx_set_mlme(struct net_
> printk(KERN_DEBUG PFX "wx_set_mlme: we should know the net here...\n");
> goto out;
> }
> - return ieee80211softmac_deauth_req(mac, net, reason);
> + err = ieee80211softmac_deauth_req(mac, net, reason);
> + goto out;
> case IW_MLME_DISASSOC:
> ieee80211softmac_send_disassoc_req(mac, reason);
> mac->associnfo.associated = 0;
> -
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