Hao Zhong created LUCENE-8536:
---------------------------------
Summary: The bytes parameter of the copy can be overflowed.
Key: LUCENE-8536
URL: https://issues.apache.org/jira/browse/LUCENE-8536
Project: Lucene - Core
Issue Type: Bug
Components: -tools
Affects Versions: trunk
Reporter: Hao Zhong
The copy method of the PagedBytes class is as follow:
{code:java}
public void copy(BytesRef bytes, BytesRef out) {
int left = blockSize - upto;
if (bytes.length > left || currentBlock==null) {
if (currentBlock != null) {
addBlock(currentBlock);
didSkipBytes = true;
}
currentBlock = new byte[blockSize];
upto = 0;
left = blockSize;
assert bytes.length <= blockSize;
// TODO: we could also support variable block sizes
}
out.bytes = currentBlock;
out.offset = upto;
out.length = bytes.length;
System.arraycopy(bytes.bytes, bytes.offset, currentBlock, upto, bytes.length);
upto += bytes.length;
}
{code}
The method does not throw exceptions for illegal inputs. In the same class, the
copyUsingLengthPrefix method checks the input value"
{code:java}
public long copyUsingLengthPrefix(BytesRef bytes) {
if (bytes.length >= 32768) {
throw new IllegalArgumentException("max length is 32767 (got " + bytes.length +
")");
}
if (upto + bytes.length + 2 > blockSize) {
if (bytes.length + 2 > blockSize) {
throw new IllegalArgumentException("block size " + blockSize + " is too small
to store length " + bytes.length + " bytes");
}
if (currentBlock != null) {
addBlock(currentBlock);
}
currentBlock = new byte[blockSize];
upto = 0;
}
final long pointer = getPointer();
if (bytes.length < 128) {
currentBlock[upto++] = (byte) bytes.length;
} else {
currentBlock[upto++] = (byte) (0x80 | (bytes.length >> 8));
currentBlock[upto++] = (byte) (bytes.length & 0xff);
}
System.arraycopy(bytes.bytes, bytes.offset, currentBlock, upto, bytes.length);
upto += bytes.length;
return pointer;
}
{code}
I understand that in the first method,
{code:java}
assert bytes.length <= blockSize;{code}
checks whether the length of the bytes is too large. However, the method does
not check blockSize either. As a result, the length of the bytes can still be
overflowed, if blockSize is too large. In addition, the second method also
checks whether
{code:java}
bytes.length + 2 > blockSize{code}
Shall the first method also checks the requirement?
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