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From:   David Laight <David.Laight@ACULAB.COM>
To:     'Dan Carpenter' <dan.carpenter@oracle.com>,
        Len Baker <len.baker@gmx.com>
CC:     Larry Finger <Larry.Finger@lwfinger.net>,
        Florian Schilhabel <florian.c.schilhabel@googlemail.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Pavel Skripkin <paskripkin@gmail.com>,
        "linux-staging@lists.linux.dev" <linux-staging@lists.linux.dev>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH] staging/rtl8712: Remove all strcpy() uses in favor of
 strscpy()
Thread-Topic: [PATCH] staging/rtl8712: Remove all strcpy() uses in favor of
 strscpy()
Thread-Index: AQHXfGBOiwzYJ/Wx2kuQ1xZyGR2EOqtKavEA
Date:   Mon, 19 Jul 2021 15:24:38 +0000
Message-ID: <de94438319a84e0985b3ba0f5c00807b@AcuMS.aculab.com>
References: <20210717155145.15041-1-len.baker@gmx.com>
 <20210719053747.GN1931@kadam>
In-Reply-To: <20210719053747.GN1931@kadam>
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From: Dan Carpenter
> Sent: 19 July 2021 06:38
...
> Not related to your patch but this code is bad.  What it does is the
> "ifname" can be set as a module parameter.  So instead of testing if it
> has been set, it uses the checking inside dev_alloc_name() to see if we
> can allocate what the user requested.  If not then set it to "wlan%d".
> If we cannot allocate what the user wants then we should return an
> error.
> 
> It should do:
> 
> 	if (ifname[0] == '\0')
> 		strscpy(ifname, "wlan%d", sizeof(ifname));
> 
> 	ret = dev_alloc_name(pnetdev, ifname);
> 	if (ret < 0) {
> 		dev_err(pnetdev, "allocating device name failed.\n");
> 		return NULL;
> 	}

I know only root can set module parameters, but having one
that contains a string used as a printf format seems
dangerous at best.

Isn't it best to let userspace rename the interfaces later on?

	David

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