linux-kernel - Re: [PATCH v3 0/4] Make sscanf() stricter

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Date:   Thu, 15 Jun 2023 14:23:59 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     David Laight <David.Laight@...lab.com>
Cc:     'Demi Marie Obenour' <demi@...isiblethingslab.com>,
        Alexey Dobriyan <adobriyan@...il.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Rasmus Villemoes <linux@...musvillemoes.dk>,
        Hans de Goede <hdegoede@...hat.com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Sakari Ailus <sakari.ailus@...ux.intel.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Juergen Gross <jgross@...e.com>,
        Stefano Stabellini <sstabellini@...nel.org>,
        Oleksandr Tyshchenko <oleksandr_tyshchenko@...m.com>,
        Lee Jones <lee@...nel.org>, Andy Lutomirski <luto@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Vincenzo Frascino <vincenzo.frascino@....com>,
        Petr Mladek <pmladek@...e.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Sergey Senozhatsky <senozhatsky@...omium.org>
Subject: Re: [PATCH v3 0/4] Make sscanf() stricter

On Thu, Jun 15, 2023 at 08:06:46AM +0000, David Laight wrote:
> From: Demi Marie Obenour
> > Sent: 14 June 2023 21:09

...

> > > What sort of formats and data are being used?
> > 
> > Base-10 or base-16 integers, with whitespace never being valid.
> 
> In which case sscanf() really isn't what you are looking for.
> 
> > > The "%s" format terminates on whitespace.
> > > Even stroul() (and friends) will skip leading whitespace.
> > 
> > Yes, which is a reason that strto*l() are just broken IMO.
> 
> They are not 'broken', that is what is useful most of the time.
> The usual problem is that "020" is treated as octal.
> 
> > I’m trying to replace their uses in Xen with custom parsing code.
> 
> Then write a custom parser :-)

Hmm... Usually we are against zillion implementations of the same with zillion
bugs hidden (each buggy implementation with its own bugs).

-- 
With Best Regards,
Andy Shevchenko