Re: [PATCH] Initialize local relocator subchunk struct to all zeros

[Alec Brown]

On Thu, Jul 14, 2022 at 03:38:04PM +0100, Darren Kenny wrote:
> Hi Ross,
> 
> This looks good to me.
> 
> On Thursday, 2022-07-14 at 09:41:28 -04, Ross Philipson wrote:
> > The way the code is written the tofree variable would never be
> > passed to the free_subchunk() function uninitialized. Coverity
> > cannot determine this and flags the situation as "Using uninitialized
> > value...". The fix is just to initialize the local struct.
> >
> > Fixes: CID 314016
> >
> > Signed-off-by: Ross Philipson <ross.philipson@oracle.com>
> 
> Reviewed-by: Darren Kenny <darren.kenny@oracle.com>

I ran this through a private Coverity scan which marked the bug as eliminated
and didn't have any issues running it on a VM.

Tested-by: Alec Brown <alec.r.brown@oracle.com>

Alec Brown

> 
> Thanks,
> 
> Darren.
> 
> > ---
> >  grub-core/lib/relocator.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/grub-core/lib/relocator.c b/grub-core/lib/relocator.c
> > index 68ef128..bfcc70d 100644
> > --- a/grub-core/lib/relocator.c
> > +++ b/grub-core/lib/relocator.c
> > @@ -989,7 +989,7 @@ malloc_in_range (struct grub_relocator *rel,
> >     if (j != 0 && events[j - 1].pos != events[j].pos)
> >       {
> >         grub_addr_t alloc_start, alloc_end;
> > -       struct grub_relocator_subchunk tofree;
> > +       struct grub_relocator_subchunk tofree = {0};
> >         struct grub_relocator_subchunk *curschu = &tofree;
> >         if (!oom)
> >           curschu = &res->subchunks[cural];
> > -- 
> > 1.8.3.1