[dm-devel] [PATCH v2] dm raid: fix parse_raid_params() variable range issue

[Mike Snitzer]

On Mon, Mar 26 2018 at  2:16pm -0400,
Mike Snitzer <snitzer at redhat.com> wrote:

> On Thu, Mar 22 2018 at  5:13pm -0400,
> Heinz Mauelshagen <heinzm at redhat.com> wrote:
> 
> > On 03/22/2018 08:41 PM, Mike Snitzer wrote:
> > >On Thu, Mar 22 2018 at  1:21pm -0400,
> > >Heinz Mauelshagen <heinzm at redhat.com> wrote:
> > >
> > >>This v2 addresses Mikulas' point about the variable range and folds in
> > >>"[PATCH] dm raid: use __within_range() more in parse_raid_params()":
> > >>
> > >>parse_raid_parames() compared variable "int value" with
> > >>INT_MAX to prevent overflow of mddev variables set.
> > >>
> > >>Change type to "long long value".
> > >Can you elaborate on the risk/issue that is being fixed here?
> > 
> > Fix addresses a coverity finding supporting the full,
> > positive range of the "struct mddev" int members
> > set here.  I.e. the "int" cast is compared with INT_MAX.
> 
> Can you cut and paste the relevant portions of the coverity report?

I've dropped this patch for now.  Until I get more insight on what the
problem is I'm not appreciating why changing to a larger data type is
the right way forward (especially if MD is just using int anyway).

Mike