On 17-07-25 08:37 AM, Jiri Pirko wrote:
Tue, Jul 25, 2017 at 02:34:58PM CEST, j...@mojatatu.com wrote:
On 17-07-25 07:33 AM, Jiri Pirko wrote:
Tue, Jul 25, 2017 at 01:22:44PM CEST, j...@mojatatu.com wrote:
[..]
What if I pass val 0x1 and selector 0x0 from userspace. I don't have the
bit selected, so you should not process it in kernel, no?
Yes, valid point. I am not sure - should we reject?
I think that the validation might check this and reject. Makes sense to
me.
How does this look? I havent tested it but covers all angles
I can think of.
static int validate_nla_bitfield32(const struct nlattr *nla,
void *valid_flags_allowed)
{
const struct nla_bitfield32 *bf = nla_data(nla);
u32 *valid_flags_mask = valid_flags_allowed;
if (!valid_flags_allowed)
return -EINVAL;
/*disallow invalid selector */
if ((bf->selector & valid_flags_allowed) >*valid_flags_allowed)
return -EINVAL;
/*disallow invalid bit values */
if (bf->value & ~*valid_flags_mask)
return -EINVAL;
/*disallow valid bit values that are not selected*/
if (bf->value & ~nbf->selector)
return -EINVAL;
return 0;
}
cheers,
jamal
