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From:   Larry Finger <Larry.Finger@lwfinger.net>
Subject: Re: [PATCH V2] rtlwifi: rtl_pci: Fix problem of too small skb->len
To:     Kalle Valo <kvalo@codeaurora.org>
Cc:     linux-wireless@vger.kernel.org, pkshih@realtek.com,
        Stable <stable@vger.kernel.org>
References: <20191020011153.29383-1-Larry.Finger@lwfinger.net>
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Date:   Sun, 20 Oct 2019 15:13:14 -0500
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On 10/20/19 3:28 AM, Kalle Valo wrote:
> Larry Finger <Larry.Finger@lwfinger.net> writes:
> 
>> In commit 8020919a9b99 ("mac80211: Properly handle SKB with radiotap
>> only"), buffers whose length is too short cause a WARN_ON(1) to be
>> executed. This change exposed a fault in rtlwifi drivers, which is fixed
>> by increasing the length of the affected buffer before it is sent to
>> mac80211.
> 
> With what frames, or in what scenarios, do you get these warnings?

I am not sure how they happen, but the firmware reports a 3-byte packet, which 
leads to the warning. After looking at the code path again, a better approach 
would be to consider those short packets the same way that those with CRC or 
hardware errors and drop them.

After more testing, I will send V3 using that approach.

Larry