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Message-ID: <1bf09d848148311a952870113401077dfc956bbd.camel@perches.com>
Subject: Re: [PATCH 11/20] hwmon: Manual replacement of the deprecated
 strlcpy() with return values
From:   Joe Perches <joe@perches.com>
To:     Guenter Roeck <linux@roeck-us.net>,
        Romain Perier <romain.perier@gmail.com>,
        Kees Cook <keescook@chromium.org>,
        kernel-hardening@lists.openwall.com
Cc:     linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org
Date:   Sun, 28 Feb 2021 03:50:44 -0800
In-Reply-To: <3b8dd556-8c09-9686-dec6-9d523a9762a8@roeck-us.net>
References: <20210222151231.22572-1-romain.perier@gmail.com>
         <20210222151231.22572-12-romain.perier@gmail.com>
         <3b8dd556-8c09-9686-dec6-9d523a9762a8@roeck-us.net>
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On Mon, 2021-02-22 at 07:46 -0800, Guenter Roeck wrote:
> On 2/22/21 7:12 AM, Romain Perier wrote:
> > The strlcpy() reads the entire source buffer first, it is dangerous if
> > the source buffer lenght is unbounded or possibility non NULL-terminated.
> 
> length
> 
> > It can lead to linear read overflows, crashes, etc...
> > 
> Not here. This description is misleading.
> 
> > As recommended in the deprecated interfaces [1], it should be replaced
> > by strscpy.
> > 
> > This commit replaces all calls to strlcpy that handle the return values
> > by the corresponding strscpy calls with new handling of the return
> > values (as it is quite different between the two functions).
> > 
> > [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
> > 
> > Signed-off-by: Romain Perier <romain.perier@gmail.com>
> 
> This patch just adds pain to injury, as the source 'buffers' are all fixed
> strings and their length will never exceed the maximum buffer length.
> I really don't see the point of using strscpy() in this situation.

Might as well just use strcpy (I'd still prefer stracpy)

https://lore.kernel.org/lkml/24bb53c57767c1c2a8f266c305a670f7@sk2.org/T/