On Wed, 2015-12-23 at 07:24 -0500, Mimi Zohar wrote: > On Wed, 2015-12-23 at 13:47 +0200, Petko Manolov wrote: > > > On 15-12-22 16:50:01, Sasha Levin wrote: > > > On 12/22/2015 04:40 PM, Petko Manolov wrote: > > > >> Thanks, Sasha. By the time ima_update_policy() is called > > > >> >ima_release_policy() has already output the policy update status > > > >> >message. I guess an empty policy could be considered a valid policy. > > > >> >Could you add a msg indicating that the new policy was empty? > > > > > > > > As far as I can say we can't get to ima_update_policy() with empty > > > > ima_temp_rules because ima_write_policy() will set valid_policy to 0 in > > > > case > > > > of an empty rule. I'll double check it tomorrow, but please you do > > > > that > > > > too. > > > > > > This is based on an actual crash rather than code analysis. > > > > I was able to reproduce the crash with: echo "" > > > /sys/kernel/security/ima/policy > > > > It turns out ima_parse_add_rule() returns 1, even though the string is > > empty > > This logic may be part of "empty policy is a valid policy" or something > > else. > > As it is more dangerous to change the behavior at this point i assume your > > patch > > is the right solution for the problem. > > > > Acked-by: Petko Manolov <pet...@mip-labs.com> > > > > Mimi, shall we change ima_parse_add_rule's behavior in the future or it's > > too > > much work? > > ima_parse_add_rules() has no way of knowing if the policy as a whole is > valid. I would define a new function in ima_policy.c to return the > number of rules being added and call it at the beginning of > ima_release_policy() before the status message. That way the number of > rules added can be included in the status message. > > For now, the function could just return have rules or no rules, instead > of the number of rules.
Sasha, could you make your fix a separate function (above ima_update_policy) and call it from ima_release_policy()? Thanks! Mimi -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
