On Thu, May 07, 2020 at 02:43:16PM -0400, Rafael Aquini wrote:
> On Thu, May 07, 2020 at 06:22:57PM +0000, Luis Chamberlain wrote:
> > On Thu, May 07, 2020 at 02:06:31PM -0400, Rafael Aquini wrote:
> > > diff --git a/kernel/sysctl.c b/kernel/sysctl.c
> > > index 8a176d8727a3..b80ab660d727 100644
> > > --- a/kernel/sysctl.c
> > > +++ b/kernel/sysctl.c
> > > @@ -1217,6 +1217,13 @@ static struct ctl_table kern_table[] = {
> > > .extra1 = SYSCTL_ZERO,
> > > .extra2 = SYSCTL_ONE,
> > > },
> > > + {
> > > + .procname = "panic_on_taint",
> > > + .data = &panic_on_taint,
> > > + .maxlen = sizeof(unsigned long),
> > > + .mode = 0644,
> > > + .proc_handler = proc_doulongvec_minmax,
> > > + },
> >
> > You sent this out before I could reply to the other thread on v1.
> > My thoughts on the min / max values, or lack here:
> >
> >
> > Valid range doesn't mean "currently allowed defined" masks.
> >
> >
> > For example, if you expect to panic due to a taint, but a new taint type
> > you want was not added on an older kernel you would be under a very
> > *false* sense of security that your kernel may not have hit such a
> > taint, but the reality of the situation was that the kernel didn't
> > support that taint flag only added in future kernels.
> >
> >
> > You may need to define a new flag (MAX_TAINT) which should be the last
> > value + 1, the allowed max values would be
> >
> >
> > (2^MAX_TAINT)-1
> >
> >
> > or
> >
> >
> > (1<<MAX_TAINT)-1
> >
> > Since this is to *PANIC* I think we do want to test ranges and ensure
> > only valid ones are allowed.
> >
>
> Ok. I'm thinking in:
>
> diff --git a/kernel/sysctl.c b/kernel/sysctl.c
> index 8a176d8727a3..ee492431e7b0 100644
> --- a/kernel/sysctl.c
> +++ b/kernel/sysctl.c
> @@ -1217,6 +1217,15 @@ static struct ctl_table kern_table[] = {
> .extra1 = SYSCTL_ZERO,
> .extra2 = SYSCTL_ONE,
> },
> + {
> + .procname = "panic_on_taint",
> + .data = &panic_on_taint,
> + .maxlen = sizeof(unsigned long),
> + .mode = 0644,
> + .proc_handler = proc_doulongvec_minmax,
> + .extra1 = SYSCTL_ZERO,
> + .extra2 = (1 << TAINT_FLAGS_COUNT << 1) - 1,
^^^^^^^^
Without that crap, obviously. Sorry. That was a screw up on my side,
when copyin' and pasting.
-- Rafael
> + },
>
>
> Would that address your concerns wrt this one?
>
> Cheers!
> -- Rafael
