Merge "libsnapshot: Validate Sequence Op data"

fs_mgr/libsnapshot/cow_api_test.cpp

@@ -1013,6 +1013,27 @@ TEST_F(CowTest, BigSeqOp) {
     ASSERT_TRUE(iter->Done());
 }
 
+TEST_F(CowTest, MissingSeqOp) {
+    CowOptions options;
+    CowWriter writer(options);
+    const int seq_len = 10;
+    uint32_t sequence[seq_len];
+    for (int i = 0; i < seq_len; i++) {
+        sequence[i] = i + 1;
+    }
+
+    ASSERT_TRUE(writer.Initialize(cow_->fd));
+
+    ASSERT_TRUE(writer.AddSequenceData(seq_len, sequence));
+    ASSERT_TRUE(writer.AddZeroBlocks(1, seq_len - 1));
+    ASSERT_TRUE(writer.Finalize());
+
+    ASSERT_EQ(lseek(cow_->fd, 0, SEEK_SET), 0);
+
+    CowReader reader;
+    ASSERT_FALSE(reader.Parse(cow_->fd));
+}
+
 TEST_F(CowTest, RevMergeOpItrTest) {
     CowOptions options;
     options.cluster_ops = 5;

fs_mgr/libsnapshot/cow_reader.cpp

@@ -413,6 +413,13 @@ bool CowReader::PrepMergeOps() {
         }
         block_map->insert({current_op.new_block, i});
     }
+    for (auto block : *merge_op_blocks) {
+        if (block_map->count(block) == 0) {
+            LOG(ERROR) << "Invalid Sequence Ops. Could not find Cow Op for new block " << block;
+            return false;
+        }
+    }
+
     if (merge_op_blocks->size() > header_.num_merge_ops) {
         num_ordered_ops_to_merge_ = merge_op_blocks->size() - header_.num_merge_ops;
     } else {