Messages in this thread | | | Subject | Re: [PATCH] IMA: policy can be updated zero times | From | Mimi Zohar <> | Date | Tue, 22 Dec 2015 14:56:28 -0500 |
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On Tue, 2015-12-22 at 08:51 -0500, Sasha Levin wrote: > Commit "IMA: policy can now be updated multiple times" assumed that the > policy would be updated at least once. > > If there are zero updates, the temporary list head object will get added > to the policy list, and later dereferenced as an IMA policy object, which > means that invalid memory will be accessed. > > Signed-off-by: Sasha Levin <sasha.levin@oracle.com> > --- > security/integrity/ima/ima_policy.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c > index ba5d2fc..9b958b8 100644 > --- a/security/integrity/ima/ima_policy.c > +++ b/security/integrity/ima/ima_policy.c > @@ -431,6 +431,9 @@ void ima_update_policy(void) > { > struct list_head *first, *last, *policy; > > + if (list_empty(&ima_temp_rules)) > + return; > + > /* append current policy with the new rules */ > first = (&ima_temp_rules)->next; > last = (&ima_temp_rules)->prev;
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?
Mimi
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