Re: [PATCH v3] vsprintf: Prevent crash when dereferencing invalid pointers

From: Andy Shevchenko
Date: Tue Apr 03 2018 - 07:56:33 EST


On Tue, 2018-04-03 at 13:52 +0200, Petr Mladek wrote:
> On Tue 2018-04-03 10:12:37, Sergey Senozhatsky wrote:
> > On (04/02/18 17:15), Andy Shevchenko wrote:
> > > >
> > > > Hmm, I have never seen the error code in this form.
> > >
> > > We have limited space to print it and error numbers currently can
> > > be up
> > > to 0xfff (4095). So, I have no better idea how to squeeze them
> > > while
> > > thinking that "(efault)" is much harder to parse in case of error
> >
> > 'efault' looks to me like a misspelled 'default', for some reason.
>
> I wonder if (-efault) would help a bit.

It's 9 characters, not going to satisfy sizeof(void *) * 2 on 32-bit
systems.

> Even better might be (-EFAULT). But then it would be better to use
> (NULL). It already was but it was explicitly changed to the lowercase
> variant by the commit 0f4f81dce93774a447da3c ("vsprintf: factorize
> "(null)" string").

--
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy