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,
+ },
Would that address your concerns wrt this one?
Cheers!
-- Rafael
