Re: [PATCH v1 1/1] vsprintf: Fix potential unaligned access

From: Sakari Ailus
Date: Tue Jan 11 2022 - 05:54:48 EST


Hi Andy,

On Tue, Jan 11, 2022 at 12:10:28PM +0200, Andy Shevchenko wrote:
> On Tue, Jan 11, 2022 at 12:12:46AM +0200, Sakari Ailus wrote:
> > On Mon, Jan 10, 2022 at 10:50:49PM +0200, Andy Shevchenko wrote:
> > > The %p4cc specifier in some cases might get an unaligned pointer.
> > > Due to this we need to make copy to local variable once to avoid
> > > potential crashes on some architectures due to improper access.
> >
> > I guess this problem exists virtually everywhere where pointers are being
> > handled: the pointer could be unaligned.
>
> True. And my patch improves the situation.
> See, for example, 0f70fe605fad ("hexdump: fix for non-aligned buffers").

This is different since there's no guarantee of a void pointer's alignment.

The pixelformat used for %p4cc is a pointer to u32.

--
Kind regards,

Sakari Ailus