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Message-ID: <abb4efba-90b4-da14-5683-3cd96819a5e0@huawei.com>
Date:   Fri, 1 Sep 2023 17:17:38 +0800
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Subject: Re: [PATCH net,v2] wifi: mac80211: fix WARNING in
 ieee80211_link_info_change_notify()
To:     Johannes Berg <johannes@sipsolutions.net>,
        <linux-wireless@vger.kernel.org>, <netdev@vger.kernel.org>,
        <davem@davemloft.net>, <edumazet@google.com>, <kuba@kernel.org>,
        <pabeni@redhat.com>
CC:     <weiyongjun1@huawei.com>, <yuehaibing@huawei.com>
References: <20230901035301.3473463-1-shaozhengchao@huawei.com>
 <7127fe5a4f2cfcdc3a55269f0a427477e264fabc.camel@sipsolutions.net>
From:   shaozhengchao <shaozhengchao@huawei.com>
In-Reply-To: <7127fe5a4f2cfcdc3a55269f0a427477e264fabc.camel@sipsolutions.net>
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On 2023/9/1 14:32, Johannes Berg wrote:
> On Fri, 2023-09-01 at 11:53 +0800, Zhengchao Shao wrote:
>>
>> diff --git a/net/mac80211/main.c b/net/mac80211/main.c
>> index 24315d7b3126..f79e2343dddd 100644
>> --- a/net/mac80211/main.c
>> +++ b/net/mac80211/main.c
>> @@ -285,6 +285,9 @@ void ieee80211_link_info_change_notify(struct ieee80211_sub_if_data *sdata,
>>   	if (!changed || sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
>>   		return;
>>   
>> +	if (!ieee80211_sdata_running(sdata))
>> +		return;
>> +
>>   	if (!check_sdata_in_driver(sdata))
>>   		return;
>>
> 
> I don't think this is right. Do you see anything else checking that it's
> running right before checking it's in the driver? :)
> 
> Why can we even get into this call at all? I think the problem is
> already in cfg80211 allowing this.
> 
> johannes
> 

Hi johannes:
	Do you mean it shouldn't be allowed to set mcast rate when dev
is stopped, as in the following code?

--- a/net/wireless/rdev-ops.h
+++ b/net/wireless/rdev-ops.h
@@ -1229,7 +1229,7 @@ rdev_set_mcast_rate(struct 
cfg80211_registered_device *rdev,
         int ret = -ENOTSUPP;

         trace_rdev_set_mcast_rate(&rdev->wiphy, dev, mcast_rate);
-       if (rdev->ops->set_mcast_rate)
+       if (rdev->ops->set_mcast_rate && netif_running(dev))
                 ret = rdev->ops->set_mcast_rate(&rdev->wiphy, dev, 
mcast_rate);
         trace_rdev_return_int(&rdev->wiphy, ret);
         return ret;


Thank you

Zhengchao Shao