From 532f5c5a547126c634fefd43bbad1dc6417678ac Mon Sep 17 00:00:00 2001
From: Mihai Maruseac <mihaimaruseac@google.com>
Date: Thu, 29 Jul 2021 22:24:39 -0700
Subject: [PATCH] Prevent nullptr deref in validation of indexes in map ops.

PiperOrigin-RevId: 387738023
Change-Id: I83d18d36a7b82ffd2a40b5124a4e5b4c72238f27
---
 tensorflow/core/kernels/map_stage_op.cc | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/tensorflow/core/kernels/map_stage_op.cc b/tensorflow/core/kernels/map_stage_op.cc
index 9411792762baa..1a2f5a8fa2247 100644
--- a/tensorflow/core/kernels/map_stage_op.cc
+++ b/tensorflow/core/kernels/map_stage_op.cc
@@ -210,9 +210,9 @@ class StagingMap : public ResourceBase {
                                    const OptionalTuple& tuple)
       TF_EXCLUSIVE_LOCKS_REQUIRED(mu_) {
     if (tuple[index].has_value()) {
-      return Status(errors::InvalidArgument(
+      return errors::InvalidArgument(
           "The tensor for index '", index, "' for key '", key.scalar<int64>()(),
-          "' was already initialized '", dtypes_.size(), "'."));
+          "' was already initialized '", dtypes_.size(), "'.");
     }
 
     return Status::OK();
@@ -220,6 +220,10 @@ class StagingMap : public ResourceBase {
 
   // Check that the indices are strictly ordered
   Status check_index_ordering(const Tensor& indices) {
+    if (indices.NumElements() == 0) {
+      return errors::InvalidArgument("Indices are empty");
+    }
+
     auto findices = indices.flat<int>();
 
     for (std::size_t i = 0; i < findices.dimension(0) - 1; ++i) {
@@ -227,8 +231,7 @@ class StagingMap : public ResourceBase {
         continue;
       }
 
-      return Status(
-          errors::InvalidArgument("Indices are not strictly ordered"));
+      return errors::InvalidArgument("Indices are not strictly ordered");
     }
 
     return Status::OK();
@@ -238,10 +241,10 @@ class StagingMap : public ResourceBase {
   Status check_memory_limit(std::size_t bytes)
       TF_EXCLUSIVE_LOCKS_REQUIRED(mu_) {
     if (has_memory_limit() && bytes > memory_limit_) {
-      return Status(errors::ResourceExhausted(
+      return errors::ResourceExhausted(
           "Attempted to insert tensors with combined size of '", bytes,
           "' bytes into Staging Area with a memory limit of '", memory_limit_,
-          "'."));
+          "'.");
     }
 
     return Status::OK();