4 files changed, 35 insertions, 8 deletions

diff --git a/security/apparmor/include/context.h b/security/apparmor/include/context.h
index a0acc23..d378bff 100644
--- a/security/apparmor/include/context.h
+++ b/security/apparmor/include/context.h
@@ -20,6 +20,7 @@
 #include <linux/sched.h>
 
 #include "policy.h"
+#include "policy_ns.h"
 
 #define cred_cxt(X) (X)->security
 #define current_cxt() cred_cxt(current_cred())
@@ -162,6 +163,11 @@ static inline struct aa_profile *aa_current_profile(void)
 	return cxt->profile;
 }
 
+static inline struct aa_ns *aa_get_current_ns(void)
+{
+	return aa_get_ns(__aa_current_profile()->ns);
+}
+
 /**
  * aa_clear_task_cxt_trans - clear transition tracking info from the cxt
  * @cxt: task context to clear (NOT NULL)
diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h
index 8fcfb3c..b0b65c5 100644
--- a/security/apparmor/include/policy.h
+++ b/security/apparmor/include/policy.h
@@ -33,6 +33,8 @@
 
 struct aa_ns;
 
+extern int unprivileged_userns_apparmor_policy;
+
 extern const char *const aa_profile_mode_names[];
 #define APPARMOR_MODE_NAMES_MAX_INDEX 4
 
@@ -297,7 +299,7 @@ static inline int AUDIT_MODE(struct aa_profile *profile)
 	return profile->audit;
 }
 
-bool policy_view_capable(void);
+bool policy_view_capable(struct aa_ns *ns);
 bool policy_admin_capable(void);
 bool aa_may_manage_policy(int op);
 
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index f852cd6..f83ba33 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -745,7 +745,7 @@ static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp
 
 static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
 {
-	if (!policy_view_capable())
+	if (!policy_view_capable(NULL))
 		return -EPERM;
 	return param_get_bool(buffer, kp);
 }
@@ -759,7 +759,7 @@ static int param_set_aabool(const char *val, const struct kernel_param *kp)
 
 static int param_get_aabool(char *buffer, const struct kernel_param *kp)
 {
-	if (!policy_view_capable())
+	if (!policy_view_capable(NULL))
 		return -EPERM;
 	return param_get_bool(buffer, kp);
 }
@@ -773,14 +773,14 @@ static int param_set_aauint(const char *val, const struct kernel_param *kp)
 
 static int param_get_aauint(char *buffer, const struct kernel_param *kp)
 {
-	if (!policy_view_capable())
+	if (!policy_view_capable(NULL))
 		return -EPERM;
 	return param_get_uint(buffer, kp);
 }
 
 static int param_get_audit(char *buffer, struct kernel_param *kp)
 {
-	if (!policy_view_capable())
+	if (!policy_view_capable(NULL))
 		return -EPERM;
 
 	if (!apparmor_enabled)
diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c
index 0125de6..f092c04 100644
--- a/security/apparmor/policy.c
+++ b/security/apparmor/policy.c
@@ -76,6 +76,7 @@
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/string.h>
+#include <linux/user_namespace.h>
 
 #include "include/apparmor.h"
 #include "include/capability.h"
@@ -89,6 +90,7 @@
 #include "include/policy_unpack.h"
 #include "include/resource.h"
 
+int unprivileged_userns_apparmor_policy = 1;
 
 const char *const aa_profile_mode_names[] = {
 	"enforce",
@@ -607,20 +609,37 @@ static int audit_policy(struct aa_profile *profile, int op, gfp_t gfp,
 			&sa, NULL);
 }
 
-bool policy_view_capable(void)
+/**
+ * policy_view_capable - check if viewing policy in at @ns is allowed
+ * ns: namespace being viewed by current task (may be NULL)
+ * Returns: true if viewing policy is allowed
+ *
+ * If @ns is NULL then the namespace being viewed is assumed to be the
+ * tasks current namespace.
+ */
+bool policy_view_capable(struct aa_ns *ns)
 {
 	struct user_namespace *user_ns = current_user_ns();
+	struct aa_ns *view_ns = aa_get_current_ns();
+	bool root_in_user_ns = uid_eq(current_euid(), make_kuid(user_ns, 0)) ||
+			       in_egroup_p(make_kgid(user_ns, 0));
 	bool response = false;
+	if (!ns)
+		ns = view_ns;
 
-	if (ns_capable(user_ns, CAP_MAC_ADMIN))
+	if (root_in_user_ns && aa_ns_visible(view_ns, ns, true) &&
+	    (user_ns == &init_user_ns ||
+	     (unprivileged_userns_apparmor_policy != 0 &&
+	      user_ns->level == view_ns->level)))
 		response = true;
+	aa_put_ns(view_ns);
 
 	return response;
 }
 
 bool policy_admin_capable(void)
 {
-	return policy_view_capable() && !aa_g_lock_policy;
+	return policy_view_capable(NULL) && !aa_g_lock_policy;
 }
 
 /**