On Tue, Sep 10, 2019 at 10:37:28AM +0100, Peter Maydell wrote:
> On Tue, 10 Sep 2019 at 10:08, Stefano Garzarella <sgarz...@redhat.com> wrote:
> >
> > This patch fixes a possible integer overflow when we calculate
> > the total size of ELF segments loaded.
> >
> > Reported-by: Coverity (CID 1405299)
> > Signed-off-by: Stefano Garzarella <sgarz...@redhat.com>
> > ---
> > Now we are limited to INT_MAX, should load_elf() returns ssize_t
> > to support bigger ELFs?
> > ---
> > include/hw/elf_ops.h | 6 ++++++
> > hw/core/loader.c | 1 +
> > 2 files changed, 7 insertions(+)
> >
> > diff --git a/include/hw/elf_ops.h b/include/hw/elf_ops.h
> > index 1496d7e753..46dd3bf413 100644
> > --- a/include/hw/elf_ops.h
> > +++ b/include/hw/elf_ops.h
> > @@ -485,6 +485,12 @@ static int glue(load_elf, SZ)(const char *name, int fd,
> > }
> > }
> >
> > + if (mem_size > INT_MAX - total_size) {
> > + error_report("ELF total segments size is too big to load "
> > + "max is %d)", INT_MAX);
> > + goto fail;
> > + }
>
> This function doesn't report issues via error_report()
> (some callers intentionally have fallback options for
> what they try to do with the file), but by returning
> a suitable error value in 'ret', so I think we should
> continue that approach rather than adding an error_report()
> call here.
I agree, maybe I can add a new macro "ELF_LOAD_TOO_BIG" and
add the error message to load_elf_strerror().
I'll send a v2.
>
> I agree that accumulating the size in an 'int' is a bit
> dubious these days.
Maybe I can send another patch to change it and wherever it's used.
Thanks,
Stefano
