Message-ID: <81467464-630a-25c4-425d-d8c5c01a739c@gmail.com>
Date:   Mon, 3 Jan 2022 01:21:32 +0300
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Subject: Re: [PATCH RFT] ieee802154: atusb: move to new USB API
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To:     Alexander Aring <alex.aring@gmail.com>
Cc:     Stefan Schmidt <stefan@datenfreihafen.org>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        linux-wpan - ML <linux-wpan@vger.kernel.org>,
        "open list:NETWORKING [GENERAL]" <netdev@vger.kernel.org>,
        kernel list <linux-kernel@vger.kernel.org>,
        "# 3.19.x" <stable@vger.kernel.org>,
        Alexander Potapenko <glider@google.com>
References: <CAG_fn=VDEoQx5c7XzWX1yaYBd5y5FrG1aagrkv+SZ03c8TfQYQ@mail.gmail.com>
 <20220102171943.28846-1-paskripkin@gmail.com>
 <CAB_54W6i9-fy8Vc-uypXPtj3Uy0VuZpidFuRH0DVoWJ8utcWiw@mail.gmail.com>
From:   Pavel Skripkin <paskripkin@gmail.com>
In-Reply-To: <CAB_54W6i9-fy8Vc-uypXPtj3Uy0VuZpidFuRH0DVoWJ8utcWiw@mail.gmail.com>
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On 1/3/22 01:15, Alexander Aring wrote:
> Hi,
> 
> On Sun, 2 Jan 2022 at 12:19, Pavel Skripkin <paskripkin@gmail.com> wrote:
>>
>> Alexander reported a use of uninitialized value in
>> atusb_set_extended_addr(), that is caused by reading 0 bytes via
>> usb_control_msg().
>>
> 
> Does there exist no way to check on this and return an error on USB
> API caller level?
> 
>> Since there is an API, that cannot read less bytes, than was requested,
>> let's move atusb driver to use it. It will fix all potintial bugs with
>> uninit values and make code more modern
>>
> 
> If this is not possible to fix with the "old" USB API then I think the
> "old" USB API needs to be fixed.
> Changing to the new USB API as "making the code more modern" is a new
> feature and is a candidate for next.
> 

It can be fixed with the old one. Something like that should work:

-	if (ret < 0) {
-		atusb->err = ret;
+	if (ret < size) {
+		atusb->err = ret < 0: ret: -ENODATA;		

But I thought, that moving to new API is better fix, just because old 
one prone to uninit value bugs if error checking is wrong


With regards,
Pavel Skripkin