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Date:   Wed, 7 Dec 2022 14:41:14 +0100
From:   Jiri Pirko <jiri@resnulli.us>
To:     Jiasheng Jiang <jiasheng@iscas.ac.cn>
Cc:     jesse.brandeburg@intel.com, anthony.l.nguyen@intel.com,
        davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com, intel-wired-lan@lists.osuosl.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net] ice: Add check for kzalloc
Message-ID: <Y5CX+kYKoXeDppNT@nanopsycho>
References: <20221207022000.44043-1-jiasheng@iscas.ac.cn>
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In-Reply-To: <20221207022000.44043-1-jiasheng@iscas.ac.cn>
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Wed, Dec 07, 2022 at 03:20:00AM CET, jiasheng@iscas.ac.cn wrote:
>On Tue, Dec 06, 2022 at 05:47:01PM +0800, Jiri Pirko wrote:
>>>As kzalloc may fail and return NULL pointer,
>>>it should be better to check the return value
>>>in order to avoid the NULL pointer dereference.
>> 
>> Okay, so? Be imperative to the code base, tell it what to do in your
>> patch description.
>
>OK, I will describe the changes by the patch in more details.

It is not about details, it is about "imperative mood".


>
>>>@@ -462,6 +462,17 @@ static struct tty_driver *ice_gnss_create_tty_driver(struct ice_pf *pf)
>>> 					       GFP_KERNEL);
>>> 		pf->gnss_serial[i] = NULL;
>>> 
>>>+		if (!pf->gnss_tty_port[i]) {
>>>+			for (j = 0; j < i; j++) {
>>>+				tty_port_destroy(pf->gnss_tty_port[j]);
>> 
>> You are destroying port which you didn't call (pf->gnss_tty_port[i])
>> for. Also, you are introducing a code duplication here with the error
>> path couple of lines below. Please convert this to goto-label error
>> path so the cleanup code is shared.
>
>I will convert this to goto-label in v2.
>But I have a question that the j is from 0 to (i - 1), and therefore only
>the initialized port will be destroyed.
>Is there any wrong?

You are right.

>
>Thanks,
>Jiang
>