[PATCH] cpukit/score: Avoid overflow in multiplication

[Kinsey Moore]

Fair enough. I'll update the patch. Thanks!

On Wed, Jan 17, 2024 at 12:45 AM Sebastian Huber <
sebastian.huber at embedded-brains.de> wrote:

> On 16.01.24 21:02, Kinsey Moore wrote:
> > The two operands are 16 bit and the result is being saved into a
> > larger type. Reduce the possibility of an overflow during multiplication
> > by using the larger type as an operand.
> > ---
> >   cpukit/score/src/objectextendinformation.c | 3 ++-
> >   1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/cpukit/score/src/objectextendinformation.c
> b/cpukit/score/src/objectextendinformation.c
> > index 414766f219..f9c51c3bec 100644
> > --- a/cpukit/score/src/objectextendinformation.c
> > +++ b/cpukit/score/src/objectextendinformation.c
> > @@ -115,7 +115,8 @@ Objects_Maximum _Objects_Extend_information(
> >      * Allocate the name table, and the objects and if it fails either
> return or
> >      * generate a fatal error depending on auto-extending being active.
> >      */
> > -  object_block_size = extend_count * information->object_size;
> > +  object_block_size = extend_count;
> > +  object_block_size *= information->object_size;
> >     new_object_block = _Workspace_Allocate( object_block_size );
> >     if ( new_object_block == NULL ) {
> >       return 0;
>
> I am not sure if a reviewer understands that this two line approach is
> there to avoid integer overflows. I would simply keep the expression as
> is and change extend_count to:
>
> uint32_t extend_count;
>
> --
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