Re: [patch] module: static checker complains about negative values

Dan Carpenter
2014-05-20T08:19:58Z

On Tue, May 20, 2014 at 11:16:04AM +0930, Rusty Russell wrote:
> Dan Carpenter <dan.carpenter@oracle.com> writes:
>
> > We cap "stat.size" at INT_MAX but we don't check for negative values so
> > my static checker complains. At this point, you already have control of
> > the kernel and if you start passing negative values here then you
> > deserve what happens next.
> >
> > On 64 bit systems the vmalloc() will definitely fail. On 32 bit systems
> > we truncate the upper 32 bits away so that could succeed. I haven't
> > followed it further than that.
> >
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> If vfs_getattr() returns a negative stat.size, we have worse problems.
>
> I'd rather see you sprinkle assertions like that into the code, so we
> can make sure that can't happen for any fs's getattr().

Yeah. I was lazy. Sorry. I can just hand edit my database to say that
i_size_read() returns a reasonable number...

regards,
dan carpenter