Merge pull request #1088 from bugsnag/PLAT-5746/jni-exc-check

Check internal JNI calls for pending exceptions and no-op

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## TBD
+
+* Check internal JNI calls for pending exceptions and no-op
+  [#1088](https://github.com/bugsnag/bugsnag-android/pull/1088)
+
 ## 5.5.1 (2021-01-21)
 
 * Alter ANR SIGQUIT handler to stop interfering with Google's ANR reporting, and to avoid unsafe JNI calls from within a signal handler

bugsnag-plugin-android-ndk/src/main/CMakeLists.txt

@@ -9,6 +9,7 @@ add_library( # Specifies the name of the library.
     jni/bugsnag_ndk.c
     jni/bugsnag.c
     jni/metadata.c
+    jni/safejni.c
     jni/event.c
     jni/handlers/signal_handler.c
     jni/handlers/cpp_handler.cpp

bugsnag-plugin-android-ndk/src/main/jni/bugsnag.c

@@ -4,6 +4,7 @@
 #include "bugsnag_ndk.h"
 #include "event.h"
 #include "metadata.h"
+#include "safejni.h"
 #include "utils/stack_unwinder.h"
 #include "utils/string.h"
 #include <jni.h>
@@ -86,20 +87,45 @@ void bugsnag_notify_env(JNIEnv *env, char *name, char *message,
   ssize_t frame_count =
       bsg_unwind_stack(bsg_configured_unwind_style(), stacktrace, NULL, NULL);
 
+  // lookup com/bugsnag/android/NativeInterface
   jclass interface_class =
-      (*env)->FindClass(env, "com/bugsnag/android/NativeInterface");
-  jmethodID notify_method = (*env)->GetStaticMethodID(
+      bsg_safe_find_class(env, "com/bugsnag/android/NativeInterface");
+  if (interface_class == NULL) {
+    return;
+  }
+
+  // lookup NativeInterface.notify()
+  jmethodID notify_method = bsg_safe_get_static_method_id(
       env, interface_class, "notify",
       "([B[BLcom/bugsnag/android/Severity;[Ljava/lang/StackTraceElement;)V");
-  jclass trace_class = (*env)->FindClass(env, "java/lang/StackTraceElement");
+  if (notify_method == NULL) {
+    return;
+  }
+
+  // lookup java/lang/StackTraceElement
+  jclass trace_class = bsg_safe_find_class(env, "java/lang/StackTraceElement");
+  if (trace_class == NULL) {
+    return;
+  }
+
+  // lookup com/bugsnag/android/Severity
   jclass severity_class =
-      (*env)->FindClass(env, "com/bugsnag/android/Severity");
-  jmethodID trace_constructor = (*env)->GetMethodID(
+      bsg_safe_find_class(env, "com/bugsnag/android/Severity");
+  if (severity_class == NULL) {
+    return;
+  }
+
+  // lookup StackTraceElement constructor
+  jmethodID trace_constructor = bsg_safe_get_method_id(
       env, trace_class, "<init>",
       "(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;I)V");
+  if (trace_constructor == NULL) {
+    return;
+  }
+
   jobjectArray trace = (*env)->NewObjectArray(
       env, (jsize)frame_count,
-      (*env)->FindClass(env, "java/lang/StackTraceElement"), NULL);
+      bsg_safe_find_class(env, "java/lang/StackTraceElement"), NULL);
 
   for (int i = 0; i < frame_count; i++) {
     bugsnag_stackframe frame = stacktrace[i];
@@ -150,10 +176,19 @@ void bugsnag_notify_env(JNIEnv *env, char *name, char *message,
 }
 
 void bugsnag_set_binary_arch(JNIEnv *env) {
+  // lookup com/bugsnag/android/NativeInterface
   jclass interface_class =
-      (*env)->FindClass(env, "com/bugsnag/android/NativeInterface");
-  jmethodID set_arch_method = (*env)->GetStaticMethodID(
+      bsg_safe_find_class(env, "com/bugsnag/android/NativeInterface");
+  if (interface_class == NULL) {
+    return;
+  }
+
+  // lookup NativeInterface.setBinaryArch()
+  jmethodID set_arch_method = bsg_safe_get_static_method_id(
       env, interface_class, "setBinaryArch", "(Ljava/lang/String;)V");
+  if (set_arch_method == NULL) {
+    return;
+  }
 
   jstring arch = (*env)->NewStringUTF(env, bsg_binary_arch());
   (*env)->CallStaticVoidMethod(env, interface_class, set_arch_method, arch);
@@ -162,10 +197,19 @@ void bugsnag_set_binary_arch(JNIEnv *env) {
 }
 
 void bugsnag_set_user_env(JNIEnv *env, char *id, char *email, char *name) {
+  // lookup com/bugsnag/android/NativeInterface
   jclass interface_class =
-      (*env)->FindClass(env, "com/bugsnag/android/NativeInterface");
-  jmethodID set_user_method =
-      (*env)->GetStaticMethodID(env, interface_class, "setUser", "([B[B[B)V");
+      bsg_safe_find_class(env, "com/bugsnag/android/NativeInterface");
+  if (interface_class == NULL) {
+    return;
+  }
+
+  // lookup NativeInterface.setUser()
+  jmethodID set_user_method = bsg_safe_get_static_method_id(
+      env, interface_class, "setUser", "([B[B[B)V");
+  if (set_user_method == NULL) {
+    return;
+  }
 
   jbyteArray jid = bsg_byte_ary_from_string(env, id);
   jbyteArray jemail = bsg_byte_ary_from_string(env, email);
@@ -208,13 +252,27 @@ jfieldID bsg_parse_jcrumb_type(JNIEnv *env, bugsnag_breadcrumb_type type,
 
 void bugsnag_leave_breadcrumb_env(JNIEnv *env, char *message,
                                   bugsnag_breadcrumb_type type) {
+  // lookup com/bugsnag/android/NativeInterface
   jclass interface_class =
-      (*env)->FindClass(env, "com/bugsnag/android/NativeInterface");
-  jmethodID leave_breadcrumb_method =
-      (*env)->GetStaticMethodID(env, interface_class, "leaveBreadcrumb",
-                                "([BLcom/bugsnag/android/BreadcrumbType;)V");
+      bsg_safe_find_class(env, "com/bugsnag/android/NativeInterface");
+  if (interface_class == NULL) {
+    return;
+  }
+
+  // lookup NativeInterface.leaveBreadcrumb()
+  jmethodID leave_breadcrumb_method = bsg_safe_get_static_method_id(
+      env, interface_class, "leaveBreadcrumb",
+      "([BLcom/bugsnag/android/BreadcrumbType;)V");
+  if (interface_class == NULL) {
+    return;
+  }
+
+  // lookup com/bugsnag/android/BreadcrumbType
   jclass type_class =
-      (*env)->FindClass(env, "com/bugsnag/android/BreadcrumbType");
+      bsg_safe_find_class(env, "com/bugsnag/android/BreadcrumbType");
+  if (interface_class == NULL) {
+    return;
+  }
 
   jobject jtype = (*env)->GetStaticObjectField(
       env, type_class, bsg_parse_jcrumb_type(env, type, type_class));

bugsnag-plugin-android-ndk/src/main/jni/bugsnag_ndk.c

@@ -10,6 +10,7 @@
 #include "handlers/cpp_handler.h"
 #include "handlers/signal_handler.h"
 #include "metadata.h"
+#include "safejni.h"
 #include "utils/serializer.h"
 #include "utils/string.h"
 
@@ -151,10 +152,21 @@ Java_com_bugsnag_android_ndk_NativeBridge_deliverReportAtPath(
   if (event != NULL) {
     char *payload = bsg_serialize_event_to_json_string(event);
     if (payload != NULL) {
+
+      // lookup com/bugsnag/android/NativeInterface
       jclass interface_class =
-          (*env)->FindClass(env, "com/bugsnag/android/NativeInterface");
-      jmethodID jdeliver_method = (*env)->GetStaticMethodID(
+          bsg_safe_find_class(env, "com/bugsnag/android/NativeInterface");
+      if (interface_class == NULL) {
+        return;
+      }
+
+      // lookup NativeInterface.deliverReport()
+      jmethodID jdeliver_method = bsg_safe_get_static_method_id(
           env, interface_class, "deliverReport", "([B[BLjava/lang/String;)V");
+      if (jdeliver_method == NULL) {
+        return;
+      }
+
       size_t payload_length = bsg_strlen(payload);
       jbyteArray jpayload = (*env)->NewByteArray(env, payload_length);
       (*env)->SetByteArrayRegion(env, jpayload, 0, payload_length,