From 3573e5c44fbd48bc518baaeb7a04f08ee04312e3 Mon Sep 17 00:00:00 2001
From: PJ Fanning <fanningpj@apache.org>
Date: Sat, 12 Mar 2022 13:57:50 +0000
Subject: [PATCH] handle case where toByteArray truncates stream because max
 len is less than stream len

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1898876 13f79535-47bb-0310-9956-ffa450edef68
---
 .../java/org/apache/poi/util/IOUtils.java     | 27 +++++++++-----
 .../java/org/apache/poi/util/TestIOUtils.java | 37 ++++++++++++++++++-
 2 files changed, 53 insertions(+), 11 deletions(-)

diff --git a/poi/src/main/java/org/apache/poi/util/IOUtils.java b/poi/src/main/java/org/apache/poi/util/IOUtils.java
index 7e1fef8990..cf40645138 100644
--- a/poi/src/main/java/org/apache/poi/util/IOUtils.java
+++ b/poi/src/main/java/org/apache/poi/util/IOUtils.java
@@ -230,7 +230,7 @@ public final class IOUtils {
             checkLength(length, derivedMaxLength);
         }
 
-        final int derivedLen = Math.min(length, derivedMaxLength);
+        final int derivedLen = isLengthKnown ? Math.min(length, derivedMaxLength) : derivedMaxLength;
         final int byteArrayInitLen = calculateByteArrayInitLength(isLengthKnown, length, derivedMaxLength);
         final int internalBufferLen = DEFAULT_BUFFER_SIZE;
         try (UnsynchronizedByteArrayOutputStream baos = new UnsynchronizedByteArrayOutputStream(byteArrayInitLen)) {
@@ -242,18 +242,15 @@ public final class IOUtils {
                 if (readBytes > 0) {
                     baos.write(buffer, 0, readBytes);
                 }
-
                 checkByteSizeLimit(totalBytes);
             } while (totalBytes < derivedLen && readBytes > -1);
 
-            if (checkEOFException) {
-                if (derivedMaxLength != Integer.MAX_VALUE && totalBytes == derivedMaxLength) {
-                    throw new IOException("MaxLength (" + derivedMaxLength + ") reached - stream seems to be invalid.");
-                }
+            if (BYTE_ARRAY_MAX_OVERRIDE < 0 && readBytes > -1 && !isLengthKnown && stream.read() >= 0) {
+                throwRecordTruncationException(derivedMaxLength);
+            }
 
-                if (derivedLen != Integer.MAX_VALUE && totalBytes < derivedLen) {
-                    throw new EOFException("unexpected EOF - expected len: " + derivedLen + " - actual len: " + totalBytes);
-                }
+            if (checkEOFException && derivedLen != Integer.MAX_VALUE && totalBytes < derivedLen) {
+                throw new EOFException("unexpected EOF - expected len: " + derivedLen + " - actual len: " + totalBytes);
             }
 
             return baos.toByteArray();
@@ -586,7 +583,7 @@ public final class IOUtils {
      * Simple utility function to check that you haven't hit EOF
      * when reading a byte.
      *
-     * @param is inputstream to read
+     * @param is input stream to read
      * @return byte read, unless
      * @throws IOException on IOException or EOF if -1 is read
      */
@@ -608,4 +605,14 @@ public final class IOUtils {
                 length, maxLength));
 
     }
+
+    private static void throwRecordTruncationException(final int maxLength) {
+        throw new RecordFormatException(String.format(Locale.ROOT, "Tried to read data but the maximum length " +
+                "for this record type is %,d.\n" +
+                "If the file is not corrupt or large, please open an issue on bugzilla to request \n" +
+                "increasing the maximum allowable size for this record type.\n"+
+                "As a temporary workaround, consider setting a higher override value with " +
+                "IOUtils.setByteArrayMaxOverride()", maxLength));
+
+    }
 }
diff --git a/poi/src/test/java/org/apache/poi/util/TestIOUtils.java b/poi/src/test/java/org/apache/poi/util/TestIOUtils.java
index 1f55e980f6..cb335921cb 100644
--- a/poi/src/test/java/org/apache/poi/util/TestIOUtils.java
+++ b/poi/src/test/java/org/apache/poi/util/TestIOUtils.java
@@ -151,6 +151,30 @@ final class TestIOUtils {
         }
     }
 
+    @Test
+    void testToByteArrayMaxLengthWithByteArrayInitLenShort() throws IOException {
+        final byte[] array = new byte[]{1, 2, 3, 4, 5, 6, 7};
+        IOUtils.setMaxByteArrayInitSize(2);
+        try (ByteArrayInputStream is = new ByteArrayInputStream(array)) {
+            assertEquals(2, IOUtils.getMaxByteArrayInitSize());
+            assertArrayEquals(array, IOUtils.toByteArrayWithMaxLength(is, 7));
+        } finally {
+            IOUtils.setMaxByteArrayInitSize(-1);
+        }
+    }
+
+    @Test
+    void testToByteArrayMaxLengthWithByteArrayInitLenLong() throws IOException {
+        final byte[] array = new byte[]{1, 2, 3, 4, 5, 6, 7};
+        IOUtils.setMaxByteArrayInitSize(8192);
+        try (ByteArrayInputStream is = new ByteArrayInputStream(array)) {
+            assertEquals(8192, IOUtils.getMaxByteArrayInitSize());
+            assertArrayEquals(array, IOUtils.toByteArrayWithMaxLength(is, 7));
+        } finally {
+            IOUtils.setMaxByteArrayInitSize(-1);
+        }
+    }
+
     @Test
     void testToByteArrayMaxLengthLongerThanArray() throws IOException {
         final byte[] array = new byte[]{1, 2, 3, 4, 5, 6, 7};
@@ -163,7 +187,18 @@ final class TestIOUtils {
     void testToByteArrayMaxLengthShorterThanArray() throws IOException {
         final byte[] array = new byte[]{1, 2, 3, 4, 5, 6, 7};
         try (ByteArrayInputStream is = new ByteArrayInputStream(array)) {
-            assertArrayEquals(new byte[]{1, 2, 3}, IOUtils.toByteArrayWithMaxLength(is, 3));
+            assertThrows(RecordFormatException.class, () -> IOUtils.toByteArrayWithMaxLength(is, 3));
+        }
+    }
+
+    @Test
+    void testToByteArrayMaxLengthShorterThanArrayWithByteArrayOverride() throws IOException {
+        final byte[] array = new byte[]{1, 2, 3, 4, 5, 6, 7};
+        IOUtils.setByteArrayMaxOverride(30 * 1024 * 1024);
+        try (ByteArrayInputStream is = new ByteArrayInputStream(array)) {
+            assertArrayEquals(array, IOUtils.toByteArrayWithMaxLength(is, 3));
+        } finally {
+            IOUtils.setByteArrayMaxOverride(-1);
         }
     }
 
-- 
2.39.5