[PATCH AUTOSEL 4.19 045/172] apparmor: fix introspection of of task mode for unconfined tasks

[Sasha Levin <sashal@kernel.org>]

From: John Johansen <john.johansen@canonical.com>

[ Upstream commit dd2569fbb053719f7df7ef8fdbb45cf47156a701 ]

Fix two issues with introspecting the task mode.

1. If a task is attached to a unconfined profile that is not the
   ns->unconfined profile then. Mode the mode is always reported
   as -

      $ ps -Z
      LABEL                               PID TTY          TIME CMD
      unconfined                         1287 pts/0    00:00:01 bash
      test (-)                           1892 pts/0    00:00:00 ps

   instead of the correct value of (unconfined) as shown below

      $ ps -Z
      LABEL                               PID TTY          TIME CMD
      unconfined                         2483 pts/0    00:00:01 bash
      test (unconfined)                  3591 pts/0    00:00:00 ps

2. if a task is confined by a stack of profiles that are unconfined
   the output of label mode is again the incorrect value of (-) like
   above, instead of (unconfined). This is because the visibile
   profile count increment is skipped by the special casing of
   unconfined.

Fixes: f1bd904175e8 ("apparmor: add the base fns() for domain labels")
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 security/apparmor/label.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/security/apparmor/label.c b/security/apparmor/label.c
index 2469549842d2..6e7aa2ef8ee0 100644
--- a/security/apparmor/label.c
+++ b/security/apparmor/label.c
@@ -1535,13 +1535,13 @@ static const char *label_modename(struct aa_ns *ns, struct aa_label *label,
 
 	label_for_each(i, label, profile) {
 		if (aa_ns_visible(ns, profile->ns, flags & FLAG_VIEW_SUBNS)) {
-			if (profile->mode == APPARMOR_UNCONFINED)
+			count++;
+			if (profile == profile->ns->unconfined)
 				/* special case unconfined so stacks with
 				 * unconfined don't report as mixed. ie.
 				 * profile_foo//&:ns1:unconfined (mixed)
 				 */
 				continue;
-			count++;
 			if (mode == -1)
 				mode = profile->mode;
 			else if (mode != profile->mode)
-- 
2.25.1