diff --git a/include/media/stagefright/ProcessInfo.h b/include/media/stagefright/ProcessInfo.h
index ec0cdff..0be1a52 100644
--- a/include/media/stagefright/ProcessInfo.h
+++ b/include/media/stagefright/ProcessInfo.h
@@ -27,6 +27,7 @@
     ProcessInfo();
 
     virtual bool getPriority(int pid, int* priority);
+    virtual bool isValidPid(int pid);
 
 protected:
     virtual ~ProcessInfo();
diff --git a/include/media/stagefright/ProcessInfoInterface.h b/include/media/stagefright/ProcessInfoInterface.h
index 222f92d..b39112a 100644
--- a/include/media/stagefright/ProcessInfoInterface.h
+++ b/include/media/stagefright/ProcessInfoInterface.h
@@ -23,6 +23,7 @@
 
 struct ProcessInfoInterface : public RefBase {
     virtual bool getPriority(int pid, int* priority) = 0;
+    virtual bool isValidPid(int pid) = 0;
 
 protected:
     virtual ~ProcessInfoInterface() {}
diff --git a/media/libmediaplayerservice/tests/DrmSessionManager_test.cpp b/media/libmediaplayerservice/tests/DrmSessionManager_test.cpp
index de350a1..ef4c833 100644
--- a/media/libmediaplayerservice/tests/DrmSessionManager_test.cpp
+++ b/media/libmediaplayerservice/tests/DrmSessionManager_test.cpp
@@ -39,6 +39,10 @@
         return true;
     }
 
+    virtual bool isValidPid(int /* pid */) {
+        return true;
+    }
+
 private:
     DISALLOW_EVIL_CONSTRUCTORS(FakeProcessInfo);
 };
diff --git a/media/libstagefright/ProcessInfo.cpp b/media/libstagefright/ProcessInfo.cpp
index 353f108..27f1a79 100644
--- a/media/libstagefright/ProcessInfo.cpp
+++ b/media/libstagefright/ProcessInfo.cpp
@@ -20,6 +20,7 @@
 
 #include <media/stagefright/ProcessInfo.h>
 
+#include <binder/IPCThreadState.h>
 #include <binder/IProcessInfoService.h>
 #include <binder/IServiceManager.h>
 
@@ -52,6 +53,12 @@
     return true;
 }
 
+bool ProcessInfo::isValidPid(int pid) {
+    int callingPid = IPCThreadState::self()->getCallingPid();
+    // Trust it if this is called from the same process otherwise pid has to match the calling pid.
+    return (callingPid == getpid()) || (callingPid == pid);
+}
+
 ProcessInfo::~ProcessInfo() {}
 
 }  // namespace android
diff --git a/services/mediaresourcemanager/ResourceManagerService.cpp b/services/mediaresourcemanager/ResourceManagerService.cpp
index 4f99860..3d4e0b5 100644
--- a/services/mediaresourcemanager/ResourceManagerService.cpp
+++ b/services/mediaresourcemanager/ResourceManagerService.cpp
@@ -206,6 +206,10 @@
     mServiceLog->add(log);
 
     Mutex::Autolock lock(mLock);
+    if (!mProcessInfo->isValidPid(pid)) {
+        ALOGE("Rejected addResource call with invalid pid.");
+        return;
+    }
     ResourceInfos& infos = getResourceInfosForEdit(pid, mMap);
     ResourceInfo& info = getResourceInfoForEdit(clientId, client, infos);
     // TODO: do the merge instead of append.
@@ -220,6 +224,10 @@
     mServiceLog->add(log);
 
     Mutex::Autolock lock(mLock);
+    if (!mProcessInfo->isValidPid(pid)) {
+        ALOGE("Rejected removeResource call with invalid pid.");
+        return;
+    }
     ssize_t index = mMap.indexOfKey(pid);
     if (index < 0) {
         ALOGV("removeResource: didn't find pid %d for clientId %lld", pid, (long long) clientId);
@@ -259,6 +267,10 @@
     Vector<sp<IResourceManagerClient>> clients;
     {
         Mutex::Autolock lock(mLock);
+        if (!mProcessInfo->isValidPid(callingPid)) {
+            ALOGE("Rejected reclaimResource call with invalid callingPid.");
+            return false;
+        }
         const MediaResource *secureCodec = NULL;
         const MediaResource *nonSecureCodec = NULL;
         const MediaResource *graphicMemory = NULL;
diff --git a/services/mediaresourcemanager/test/ResourceManagerService_test.cpp b/services/mediaresourcemanager/test/ResourceManagerService_test.cpp
index df49ddc..cffedc6 100644
--- a/services/mediaresourcemanager/test/ResourceManagerService_test.cpp
+++ b/services/mediaresourcemanager/test/ResourceManagerService_test.cpp
@@ -44,6 +44,10 @@
         return true;
     }
 
+    virtual bool isValidPid(int /* pid */) {
+        return true;
+    }
+
 private:
     DISALLOW_EVIL_CONSTRUCTORS(TestProcessInfo);
 };