vertx-mssql-client RowResultDecoder issue with decoding NBC rows with nullable columns containing null

[seulbdoowle]

Version

4.5 and 5.x

Context

java.lang.IndexOutOfBoundsException: index: 16, length: 1280 (expected: range(0, 85))
	at io.netty.buffer.AbstractByteBuf.checkRangeBounds(AbstractByteBuf.java:1390)
	at io.netty.buffer.AbstractByteBuf.checkIndex0(AbstractByteBuf.java:1397)
	at io.netty.buffer.AbstractUnpooledSlicedByteBuf.getCharSequence(AbstractUnpooledSlicedByteBuf.java:263)
	at io.netty.buffer.AbstractByteBuf.readCharSequence(AbstractByteBuf.java:518)
	at io.vertx.mssqlclient.impl.codec.DataType$31.decodeValue(DataType.java:838)
	at io.vertx.mssqlclient.impl.codec.DataType$28.decodeValue(DataType.java:773)
	at io.vertx.mssqlclient.impl.codec.RowResultDecoder.decodeMssqlNbcRow(RowResultDecoder.java:80)
	at io.vertx.mssqlclient.impl.codec.RowResultDecoder.decodeRow(RowResultDecoder.java:37)
	at io.vertx.sqlclient.impl.RowDecoder.handleRow(RowDecoder.java:58)
	at io.vertx.mssqlclient.impl.codec.QueryCommandBaseCodec.handleNbcRow(QueryCommandBaseCodec.java:48)
	at io.vertx.mssqlclient.impl.codec.ExtendedCursorQueryCommandCodec.handleNbcRow(ExtendedCursorQueryCommandCodec.java:173)
	at io.vertx.mssqlclient.impl.codec.MSSQLCommandCodec.decode(MSSQLCommandCodec.java:57)
	at io.vertx.mssqlclient.impl.codec.TdsMessageDecoder.decodeMessage(TdsMessageDecoder.java:75)
	at io.vertx.mssqlclient.impl.codec.TdsMessageDecoder.channelRead(TdsMessageDecoder.java:47)
	at io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:251)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:442)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
	at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:346)
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:318)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
	at io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1475)
	at io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1338)
	at io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1387)
	at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:530)
	at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:469)
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:290)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:444)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:412)
	at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1407)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:440)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:420)
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:918)
	at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166)
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:788)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:724)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:650)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:562)
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:994)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.base/java.lang.Thread.run(Thread.java:833)

From openspecs (2.2.7.15: https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-tds/c0da3cc9-4441-476b-aa99-5a518f22dc0a) it says:
The null bitmap contains one bit for each column defined in COLMETADATA.

But there may be an additional column next to the defined columns called ROWSTAT. If this column is present, it is one more column.

Possible fix
Methode decodeMssqlNbcRow Line 71:
Actual implementation:
int nullBitmapByteCount = ((len - 1) >> 3) + 1;
Should be:
int nullBitmapByteCount = ((len - (desc.hasRowStat() ? 0 : 1)) >> 3) + 1;

Steps to reproduce

1. The number of columns in the tables must be a multiple of 8 (8, 16, 24, ...)
2. The table must contain nullable columns
3. There must be columns with the content NULL

Do you have a reproducer?

No response

[tsegismont]

Thanks for the report and the detailed analysis @seulbdoowle , I'll look into it

[tsegismont]

@seulbdoowle could you share your table DDL and query SQL to be able to reproduce?

[tsegismont]

Forget it, I was able to create a producer

[tsegismont]

Fixed by #1585