[RESTRICT AUTOMERGE] CTS test for Android security b/161894517

Bug: 161894517
Bug: 163559994
Test: Ran the new testcase on android-10.0.0_r1 with/without patch

Change-Id: Ia6bed3942ea5dd8f3f82f1a12167b59ed2accbec
(cherry picked from commit 2deadb3d8d5ea5176fe509975073e786222f4f80)
diff --git a/hostsidetests/securitybulletin/AndroidTest.xml b/hostsidetests/securitybulletin/AndroidTest.xml
index 24a1e48..31449f6 100644
--- a/hostsidetests/securitybulletin/AndroidTest.xml
+++ b/hostsidetests/securitybulletin/AndroidTest.xml
@@ -252,6 +252,12 @@
         <!-- Bulletin 2020-03 -->
         <!-- Please add tests solely from this bulletin below to avoid merge conflict -->
         <option name="push" value="CVE-2020-0069->/data/local/tmp/CVE-2020-0069" />
+
+        <!--__________________-->
+        <!-- Bulletin 2020-10 -->
+        <!-- Please add tests solely from this bulletin below to avoid merge conflict -->
+        <option name="push" value="CVE-2020-0421->/data/local/tmp/CVE-2020-0421" />
+
         <option name="append-bitness" value="true" />
     </target_preparer>
 
diff --git a/hostsidetests/securitybulletin/securityPatch/CVE-2020-0421/Android.bp b/hostsidetests/securitybulletin/securityPatch/CVE-2020-0421/Android.bp
new file mode 100644
index 0000000..b4aee1e
--- /dev/null
+++ b/hostsidetests/securitybulletin/securityPatch/CVE-2020-0421/Android.bp
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+cc_test {
+    name: "CVE-2020-0421",
+    defaults: ["cts_hostsidetests_securitybulletin_defaults"],
+    srcs: ["poc.cpp"],
+    shared_libs: [
+        "libutils",
+    ],
+}
diff --git a/hostsidetests/securitybulletin/securityPatch/CVE-2020-0421/poc.cpp b/hostsidetests/securitybulletin/securityPatch/CVE-2020-0421/poc.cpp
new file mode 100644
index 0000000..09e7f60
--- /dev/null
+++ b/hostsidetests/securitybulletin/securityPatch/CVE-2020-0421/poc.cpp
@@ -0,0 +1,51 @@
+/**
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <dlfcn.h>
+
+#include "utils/String8.h"
+
+#define VULNERABLE_STRING "Q0bRTMaNUg"
+
+typedef int (*vsnprintf_t)(char *const, size_t, const char *, va_list);
+
+static vsnprintf_t fptr = nullptr;
+
+// For CVE-2020-0421 to be reproducible, the vsnprintf has to return a negative
+// value. This negative value is added to size_t resulting in runtime error.
+// Getting vsnprintf to return -1 is tricky. The issue produced in fuzzer was
+// due to the call str1.appendFormat("%S", "string"). Using wide char string
+// format specifier for regular string is not a reliable way to produce the
+// issue. As from N1570, "If any argument is not the correct type for the
+// corresponding conversion specification or If there are insufficient arguments
+// for the format, the printf behavior is undefined." The below intercepting
+// function offers a simple way to return negative value.
+int vsnprintf(char *const dest, size_t size, const char *format, va_list ap) {
+  if (!strcmp(format, VULNERABLE_STRING)) {
+    return -1;
+  }
+  return (*fptr)(dest, size, format, ap);
+}
+
+int main(void) {
+  fptr = reinterpret_cast<vsnprintf_t>(dlsym(RTLD_NEXT, "vsnprintf"));
+  if (!fptr) {
+    return EXIT_FAILURE;
+  }
+  android::String8 str1{VULNERABLE_STRING};
+  str1.appendFormat(VULNERABLE_STRING);
+  return EXIT_SUCCESS;
+}
diff --git a/hostsidetests/securitybulletin/src/android/security/cts/TestMedia.java b/hostsidetests/securitybulletin/src/android/security/cts/TestMedia.java
index e39de6b..bbc21b1 100644
--- a/hostsidetests/securitybulletin/src/android/security/cts/TestMedia.java
+++ b/hostsidetests/securitybulletin/src/android/security/cts/TestMedia.java
@@ -45,6 +45,21 @@
      ******************************************************************************/
 
     /**
+     * b/161894517
+     * Vulnerability Behaviour: SIGABRT in self
+     */
+    @SecurityTest(minPatchLevel = "2020-10")
+    @Test
+    public void testPocCVE_2020_0421() throws Exception {
+        String signals[] = {CrashUtils.SIGSEGV, CrashUtils.SIGBUS, CrashUtils.SIGABRT};
+        String binaryName = "CVE-2020-0421";
+        AdbUtils.pocConfig testConfig = new AdbUtils.pocConfig(binaryName, getDevice());
+        testConfig.config = new CrashUtils.Config().setProcessPatterns(binaryName);
+        testConfig.config.setSignals(signals);
+        AdbUtils.runPocAssertNoCrashesNotVulnerable(testConfig);
+    }
+
+    /**
      * b/132082342
      * Vulnerability Behaviour: SIGSEGV in self
      */