[impala] 12/20: IMPALA-5031: Fix undefined behavior: memset NULL

[ta...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

tarmstrong pushed a commit to branch 2.x
in repository https://gitbox.apache.org/repos/asf/impala.git

commit 58ae370e93cead3930960a490bb3824a0e08ac72
Author: Jim Apple <jb...@apache.org>
AuthorDate: Sun Jul 15 18:32:52 2018 -0700

    IMPALA-5031: Fix undefined behavior: memset NULL
    
    memset has undefined behavior when its first argument is NULL. The
    instance fixed here was found by Clang's undefined behavior
    sanitizer.
    
    It was found in the end-to-end tests. The interesting part of the
    stack trace is:
    
    /exec/data-source-scan-node.cc:152:10: runtime error: null pointer passed as argument 1, which is declared to never be null
    /usr/include/string.h:62:79: note: nonnull attribute specified here
        #0 0x482fd8e in DataSourceScanNode::GetNextInputBatch() /exec/data-source-scan-node.cc:152:3
        #1 0x482fb40 in DataSourceScanNode::Open(RuntimeState*) /exec/data-source-scan-node.cc:124:10
        #2 0x47ef854 in AggregationNode::Open(RuntimeState*) /exec/aggregation-node.cc:71:49
        #3 0x23506a4 in FragmentInstanceState::Open() /runtime/fragment-instance-state.cc:266:53
        #4 0x234b6a8 in FragmentInstanceState::Exec() /runtime/fragment-instance-state.cc:81:12
        #5 0x236ee52 in QueryState::ExecFInstance(FragmentInstanceState*) /runtime/query-state.cc:401:24
        #6 0x237093e in QueryState::StartFInstances()::$_0::operator()() const /runtime/query-state.cc:341:44
    
    Change-Id: I18fa02dc887a42a94c6f81e4923d17568f2184f2
    Reviewed-on: http://gerrit.cloudera.org:8080/10948
    Reviewed-by: Jim Apple <jb...@apache.org>
    Tested-by: Impala Public Jenkins <im...@cloudera.com>
---
 be/src/exec/data-source-scan-node.cc |  3 ++-
 be/src/util/ubsan.h                  | 37 ++++++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/be/src/exec/data-source-scan-node.cc b/be/src/exec/data-source-scan-node.cc
index 4b967bb..7d3bbf1 100644
--- a/be/src/exec/data-source-scan-node.cc
+++ b/be/src/exec/data-source-scan-node.cc
@@ -33,6 +33,7 @@
 #include "runtime/tuple-row.h"
 #include "util/jni-util.h"
 #include "util/periodic-counter-updater.h"
+#include "util/ubsan.h"
 #include "util/runtime-profile-counters.h"
 
 #include "common/names.h"
@@ -149,7 +150,7 @@ Status DataSourceScanNode::GetNextInputBatch() {
   input_batch_.reset(new TGetNextResult());
   next_row_idx_ = 0;
   // Reset all the indexes into the column value arrays to 0
-  memset(cols_next_val_idx_.data(), 0, sizeof(int) * cols_next_val_idx_.size());
+  Ubsan::MemSet(cols_next_val_idx_.data(), 0, sizeof(int) * cols_next_val_idx_.size());
   TGetNextParams params;
   params.__set_scan_handle(scan_handle_);
   RETURN_IF_ERROR(data_source_executor_->GetNext(params, input_batch_.get()));
diff --git a/be/src/util/ubsan.h b/be/src/util/ubsan.h
new file mode 100644
index 0000000..78f6bc1
--- /dev/null
+++ b/be/src/util/ubsan.h
@@ -0,0 +1,37 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you 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.
+
+#ifndef UTIL_UBSAN_H_
+#define UTIL_UBSAN_H_
+
+// Utilities mimicking parts of the standard prone to accidentally using in a way causeing
+// undefined behavior.
+
+#include <cstring>
+
+class Ubsan {
+ public:
+  static void* MemSet(void* s, int c, size_t n) {
+    if (s == nullptr) {
+      DCHECK_EQ(n, 0);
+      return s;
+    }
+    return std::memset(s, c, n);
+  }
+};
+
+#endif // UTIL_UBSAN_H_