Re: [PATCH 2/2] LSM: SafeSetID: Add setgroups() security policy handling

On Mon, Jun 13, 2022 at 02:00:03PM -0700, Micah Morton wrote:

On Mon, Jun 13, 2022 at 1:28 PM Micah Morton [off-list ref] wrote:
[...]

quoted

+static int safesetid_task_fix_setgroups(struct cred *new, const struct cred *old)
+{
+       int i;
+
+       /* Do nothing if there are no setgid restrictions for our old RGID. */
+       if (setid_policy_lookup((kid_t){.gid = old->gid}, INVALID_ID, GID) == SIDPOL_DEFAULT)
+               return 0;
+
+       get_group_info(new->group_info);
+       for (i = 0; i < new->group_info->ngroups; i++) {
+               if (!id_permitted_for_cred(old, (kid_t){.gid = group_info->gid[i]}, GID)) {

Oops, should be:

!id_permitted_for_cred(old, (kid_t){.gid = new->group_info->gid[i]}, GID)

Guess I won't send a whole new patch just for that one line

This begs the question: are there self-tests for this LSM somewhere?
It'd be really nice to add them to tool/testing/selftests ...

-- 
Kees Cook