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HTTP/2: handle zero WINDOW_UPDATE increment #634

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Merged
arturobernalg merged 1 commit into from
Feb 23, 2026
Merged

HTTP/2: handle zero WINDOW_UPDATE increment #634

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11 changes: 10 additions & 1 deletion ...ore5-h2/src/main/java/org/apache/hc/core5/http2/impl/nio/AbstractH2StreamMultiplexer.java
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Original file line number Diff line number Diff line change
Expand Up @@ -878,7 +878,15 @@ private void consumeFrame(final RawFrame frame) throws HttpException, IOExceptio
}
final int delta = payload.getInt() & 0x7fffffff;
if (delta == 0) {
throw new H2ConnectionException(H2Error.PROTOCOL_ERROR, "Invalid WINDOW_UPDATE delta");
if (streamId == 0) {
throw new H2ConnectionException(H2Error.PROTOCOL_ERROR, "Invalid WINDOW_UPDATE delta");
}
final H2Stream stream = streams.lookup(streamId);
if (stream != null) {
stream.localReset(new H2StreamResetException(H2Error.PROTOCOL_ERROR, "Invalid WINDOW_UPDATE delta"));
requestSessionOutput();
}
break;
}
if (streamId == 0) {
try {
Expand Down Expand Up @@ -947,6 +955,7 @@ private void consumeFrame(final RawFrame frame) throws HttpException, IOExceptio
throw new H2ConnectionException(H2Error.PROTOCOL_ERROR, "Illegal stream id");
}
if (frame.isFlagSet(FrameFlag.ACK)) {
// RFC 9113, Section 6.5: SETTINGS with ACK set MUST have an empty payload.
final ByteBuffer payload = frame.getPayload();
if (payload != null && payload.hasRemaining()) {
throw new H2ConnectionException(H2Error.FRAME_SIZE_ERROR, "Invalid SETTINGS ACK payload");
Expand Down
57 changes: 55 additions & 2 deletions ...-h2/src/test/java/org/apache/hc/core5/http2/impl/nio/TestAbstractH2StreamMultiplexer.java
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Original file line number Diff line number Diff line change
Expand Up @@ -380,9 +380,8 @@ void testZeroIncrement() throws Exception {
final RawFrame incrementFrame = new RawFrame(FrameType.WINDOW_UPDATE.getValue(), 0, 1, payload);
outBuffer.write(incrementFrame, writableChannel);

final H2ConnectionException exception = Assertions.assertThrows(H2ConnectionException.class, () ->
Assertions.assertDoesNotThrow(() ->
streamMultiplexer.onInput(ByteBuffer.wrap(writableChannel.toByteArray())));
Assertions.assertEquals(H2Error.PROTOCOL_ERROR, H2Error.getByCode(exception.getCode()));
}

@Test
Expand Down Expand Up @@ -1810,4 +1809,58 @@ void testGoAwayReservedBitInLastStreamIdAffectsStreamCulling() throws Exception
Assertions.assertInstanceOf(org.apache.hc.core5.http.RequestNotExecutedException.class, exceptionCaptor.getValue());
}

@Test
void testWindowUpdateZeroIncrementOnConnectionIsConnectionError() throws Exception {
final AbstractH2StreamMultiplexer mux = new H2StreamMultiplexerImpl(
protocolIOSession,
FRAME_FACTORY,
StreamIdGenerator.ODD,
httpProcessor,
CharCodingConfig.DEFAULT,
H2Config.custom().build(),
h2StreamListener,
() -> streamHandler);

final ByteBuffer payload = ByteBuffer.allocate(4);
payload.putInt(0);
payload.flip();

final RawFrame windowUpdate = new RawFrame(FrameType.WINDOW_UPDATE.getValue(), 0, 0, payload);

final H2ConnectionException ex = Assertions.assertThrows(
H2ConnectionException.class,
() -> mux.onInput(ByteBuffer.wrap(encodeFrame(windowUpdate))));

Assertions.assertEquals(H2Error.PROTOCOL_ERROR, H2Error.getByCode(ex.getCode()));
}

@Test
void testWindowUpdateZeroIncrementOnStreamIsStreamError() throws Exception {
final AbstractH2StreamMultiplexer mux = new H2StreamMultiplexerImpl(
protocolIOSession,
FRAME_FACTORY,
StreamIdGenerator.ODD,
httpProcessor,
CharCodingConfig.DEFAULT,
H2Config.custom().build(),
h2StreamListener,
() -> streamHandler);

final H2StreamChannel channel = mux.createChannel(1);
mux.createStream(channel, streamHandler);

final ByteBuffer payload = ByteBuffer.allocate(4);
payload.putInt(0);
payload.flip();

final RawFrame windowUpdate = new RawFrame(FrameType.WINDOW_UPDATE.getValue(), 0, 1, payload);

Assertions.assertDoesNotThrow(() -> mux.onInput(ByteBuffer.wrap(encodeFrame(windowUpdate))));

Mockito.verify(streamHandler).failed(exceptionCaptor.capture());
final Exception cause = exceptionCaptor.getValue();
Assertions.assertInstanceOf(H2StreamResetException.class, cause);
Assertions.assertEquals(H2Error.PROTOCOL_ERROR, H2Error.getByCode(((H2StreamResetException) cause).getCode()));
}

}
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