On 03/07/16 at 03:30pm, Kees Cook wrote:
> On Fri, Mar 4, 2016 at 8:25 AM, Baoquan He <b...@redhat.com> wrote:
> > When process 32 bit relocation tables a local variable 'extended'
> > is defined to calculate the physical address of relocs entry.
> > However its type is 'int' which is enough for i386, but not enough
> > for x86_64. That's why relocation can only be handled under 2G.
> > Otherwise a overflow will happen and cause system hang.
> >
> > Here change it to 'long' as 32 bit inverse relocation processing
> > does, and this change is safe for i386 relocation handling.
> >
> > Signed-off-by: Baoquan He <b...@redhat.com>
>
> Acked-by: Kees Cook <keesc...@chromium.org>
>
> This patch should probably be moved up into the start of this series
> instead of living in the middle here, since it's a clear stand-alone
> bug fix.
Of course. Will put it in the start of this series.
Thanks.
>
> -Kees
>
> > ---
> > arch/x86/boot/compressed/misc.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/x86/boot/compressed/misc.c
> > b/arch/x86/boot/compressed/misc.c
> > index 4b2cd0c..70445c3 100644
> > --- a/arch/x86/boot/compressed/misc.c
> > +++ b/arch/x86/boot/compressed/misc.c
> > @@ -298,7 +298,7 @@ static void handle_relocations(void *output, unsigned
> > long output_len)
> > * So we work backwards from the end of the decompressed image.
> > */
> > for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--)
> > {
> > - int extended = *reloc;
> > + long extended = *reloc;
> > extended += map;
> >
> > ptr = (unsigned long)extended;
> > --
> > 2.5.0
> >
>
>
>
> --
> Kees Cook
> Chrome OS & Brillo Security
