Re: Re: [PATCH] staging: rtl8712: check register_netdev() return value

From: shaojie . dong
Date: Thu Dec 10 2020 - 10:21:53 EST


Hi

Thanks ! I will modify sign name correctly later

Sorry to say that I have no rtl8712 hardware, so that I could not test it.

From Dan Carpenter's email reply, "free_netdev(adapter->pnetdev)" function may cause use after free issue
So that I reply email to ensure if this return value should be check or how to handle this return value error


> -----原始邮件-----
&gt; 发件人: "Greg KH" <gregkh@xxxxxxxxxxxxxxxxxxx>
&gt; 发送时间: 2020-12-09 23:13:40 (星期三)
&gt; 收件人: shaojie.dong@xxxxxxxxxxxxxxxx
&gt; 抄送: Larry.Finger@xxxxxxxxxxxx, florian.c.schilhabel@xxxxxxxxxxxxxx, devel@xxxxxxxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx
&gt; 主题: Re: [PATCH] staging: rtl8712: check register_netdev() return value
&gt;
&gt; On Wed, Dec 09, 2020 at 11:01:24PM +0800, shaojie.dong@xxxxxxxxxxxxxxxx wrote:
&gt; &gt; From: "shaojie.dong" <shaojie.dong@xxxxxxxxxxxxxxxx>
&gt; &gt;
&gt; &gt; Function register_netdev() can fail, so we should check it's return value
&gt; &gt;
&gt; &gt; Signed-off-by: shaojie.dong <shaojie.dong@xxxxxxxxxxxxxxxx>
&gt;
&gt; I doubt you sign your name with a '.' in it, right?
&gt;
&gt; Please resend with the correct name, and using Capital letters where
&gt; needed.
&gt;
&gt; &gt; ---
&gt; &gt; drivers/staging/rtl8712/hal_init.c | 5 ++++-
&gt; &gt; 1 file changed, 4 insertions(+), 1 deletion(-)
&gt; &gt;
&gt; &gt; diff --git a/drivers/staging/rtl8712/hal_init.c b/drivers/staging/rtl8712/hal_init.c
&gt; &gt; index 715f1fe8b..38a3e3d44 100644
&gt; &gt; --- a/drivers/staging/rtl8712/hal_init.c
&gt; &gt; +++ b/drivers/staging/rtl8712/hal_init.c
&gt; &gt; @@ -45,7 +45,10 @@ static void rtl871x_load_fw_cb(const struct firmware *firmware, void *context)
&gt; &gt; }
&gt; &gt; adapter-&gt;fw = firmware;
&gt; &gt; /* firmware available - start netdev */
&gt; &gt; - register_netdev(adapter-&gt;pnetdev);
&gt; &gt; + if (register_netdev(adapter-&gt;pnetdev) != 0) {
&gt; &gt; + netdev_err(adapter-&gt;pnetdev, "register_netdev() failed\n");
&gt; &gt; + free_netdev(adapter-&gt;pnetdev);
&gt; &gt; + }
&gt;
&gt; Did you test this to see if this really properly cleans everything up?
&gt;
&gt; And your if statement can be simplified, please do so.
&gt;
&gt; thanks,
&gt;
&gt; greg k-h
</shaojie.dong@xxxxxxxxxxxxxxxx></shaojie.dong@xxxxxxxxxxxxxxxx></gregkh@xxxxxxxxxxxxxxxxxxx>