Make default permission checks in performance service more restrictive.

- Check sending process in unrestricted policies.
- Allow IsTrustedUid() to cache results for better runtime efficiency.
- Update tests to verify unrestricted policy behavior.

Bug: 62468109
Test: performance_service_tests passes.
Change-Id: I0614879c8bde35ffeda2f673a3da68092433dc1a

diff --git a/services/vr/performanced/performance_service.cpp b/services/vr/performanced/performance_service.cpp
index 3f7009a..4b9fbe0 100644 (file)
--- a/services/vr/performanced/performance_service.cpp
+++ b/services/vr/performanced/performance_service.cpp
@@ -63,7 +63,7 @@ struct GroupId {
 // Returns true if the sender's euid is trusted according to VR manager service.
 struct Trusted {
   static bool Check(const Message& sender, const Task&) {
-    return IsTrustedUid(sender.GetEffectiveUserId(), false);
+    return IsTrustedUid(sender.GetEffectiveUserId());
   }
 };
 

diff --git a/services/vr/performanced/performance_service.h b/services/vr/performanced/performance_service.h
index b812535..b28d94a 100644 (file)
--- a/services/vr/performanced/performance_service.h
+++ b/services/vr/performanced/performance_service.h
@@ -53,10 +53,13 @@ class PerformanceService : public pdx::ServiceBase<PerformanceService> {
         permission_check;
 
     // Check the permisison of the given task to use this scheduler class. If a
-    // permission check function is not set then all tasks are allowed.
-    bool IsAllowed(const pdx::Message& message, const Task& task) const {
+    // permission check function is not set then operations are only allowed on
+    // tasks in the sender's process.
+    bool IsAllowed(const pdx::Message& sender, const Task& task) const {
       if (permission_check)
-        return permission_check(message, task);
+        return permission_check(sender, task);
+      else if (!task || task.thread_group_id() != sender.GetProcessId())
+        return false;
       else
         return true;
     }

diff --git a/services/vr/performanced/performance_service_tests.cpp b/services/vr/performanced/performance_service_tests.cpp
index 7de1f08..274a1b3 100644 (file)
--- a/services/vr/performanced/performance_service_tests.cpp
+++ b/services/vr/performanced/performance_service_tests.cpp
@@ -183,6 +183,17 @@ TEST(PerformanceTest, Permissions) {
   ASSERT_EQ(AID_ROOT, original_uid)
       << "This test must run as root to function correctly!";
 
+  // Test unprivileged policies on a task that does not belong to this process.
+  // Use the init process (task_id=1) as the target.
+  error = dvrSetSchedulerPolicy(1, "batch");
+  EXPECT_EQ(-EINVAL, error);
+  error = dvrSetSchedulerPolicy(1, "background");
+  EXPECT_EQ(-EINVAL, error);
+  error = dvrSetSchedulerPolicy(1, "foreground");
+  EXPECT_EQ(-EINVAL, error);
+  error = dvrSetSchedulerPolicy(1, "normal");
+  EXPECT_EQ(-EINVAL, error);
+
   // Switch the uid/gid to an id that should not have permission to access any
   // privileged actions.
   ASSERT_EQ(0, setresgid(AID_NOBODY, AID_NOBODY, -1))