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Message-ID: <84669e9c-81f7-3a56-ea57-39df3e131b3f@huawei.com>
Date:   Fri, 2 Dec 2022 10:48:12 +0800
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Subject: Re: [PATCH] wifi: mac80211: fix memory leak in
 ieee80211_register_hw()
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:     <sara.sharon@intel.com>, <luciano.coelho@intel.com>,
        <weiyongjun1@huawei.com>, <yuehaibing@huawei.com>
References: <20221122091142.261354-1-shaozhengchao@huawei.com>
 <4f37f422a0bcd8d1d2dd1bb992be30a16d335a3f.camel@sipsolutions.net>
From:   shaozhengchao <shaozhengchao@huawei.com>
In-Reply-To: <4f37f422a0bcd8d1d2dd1bb992be30a16d335a3f.camel@sipsolutions.net>
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On 2022/12/1 20:52, Johannes Berg wrote:
> On Tue, 2022-11-22 at 17:11 +0800, Zhengchao Shao wrote:
>>
>> +++ b/net/mac80211/iface.c
>> @@ -2326,8 +2326,6 @@ void ieee80211_remove_interfaces(struct ieee80211_local *local)
>>   	WARN(local->open_count, "%s: open count remains %d\n",
>>   	     wiphy_name(local->hw.wiphy), local->open_count);
>>   
>> -	ieee80211_txq_teardown_flows(local);
> 
> 
> This is after shutting down interfaces.
> 
>> @@ -1469,6 +1470,7 @@ void ieee80211_unregister_hw(struct ieee80211_hw *hw)
>>   	 * because the driver cannot be handing us frames any
>>   	 * more and the tasklet is killed.
>>   	 */
>> +	ieee80211_txq_teardown_flows(local);
>>   	ieee80211_remove_interfaces(local);
>>
> 
> But now it's before. Why is that safe?
> 
> johannes
Hi johannes:
	Thank you for your review. This change may be unsafe.
Driver do clear its reource must be after hardware stop. Remove
it before shutdown interface is unsafe. I will change in V2.

Zhengchao Shao