Skip to content

Fix use-after-free in IOTransport::OnRead on client disconnect #198548

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
JDevlieghere merged 2 commits into from
May 20, 2026
Merged

Fix use-after-free in IOTransport::OnRead on client disconnect #198548

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
eef8ee6
Fix use after free in MCP
youngd007 May 19, 2026
1e61239
Move to a local variable
youngd007 May 19, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 4 additions & 2 deletions lldb/include/lldb/Host/JSONTransport.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -259,9 +259,11 @@ template <typename Proto> class IOTransport : public JSONTransport<Proto> {
if (!m_buffer.empty())
handler.OnError(llvm::make_error<TransportUnhandledContentsError>(
std::string(m_buffer.str())));
// Move the read handle to a local before notifying the handler. The
// handler may destroy this transport (e.g. by erasing it from a
// connection map), so accessing members after OnClosed() is unsafe.
auto read_handle = std::move(m_read_handle);
handler.OnClosed();
// On EOF, remove the read handle from the MainLoop.
m_read_handle.reset();
}
}

Expand Down
18 changes: 18 additions & 0 deletions lldb/unittests/Host/JSONTransportTest.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -479,6 +479,15 @@ TEST_F(HTTPDelimitedJSONTransportTest, ReadWithEOF) {
ASSERT_THAT_ERROR(Run(), Succeeded());
}

TEST_F(HTTPDelimitedJSONTransportTest, ReadWithEOFDestroyTransportOnClose) {
input.CloseWriteFileDescriptor();
EXPECT_CALL(message_handler, OnClosed()).WillOnce([this]() {
transport.reset();
loop.RequestTermination();
});
ASSERT_THAT_ERROR(loop.Run().takeError(), Succeeded());
}

TEST_F(HTTPDelimitedJSONTransportTest, ReaderWithUnhandledData) {
std::string json = R"json({"str": "foo"})json";
std::string message =
Expand Down Expand Up @@ -588,6 +597,15 @@ TEST_F(JSONRPCTransportTest, ReadWithEOF) {
ASSERT_THAT_ERROR(Run(), Succeeded());
}

TEST_F(JSONRPCTransportTest, ReadWithEOFDestroyTransportOnClose) {
input.CloseWriteFileDescriptor();
EXPECT_CALL(message_handler, OnClosed()).WillOnce([this]() {
transport.reset();
loop.RequestTermination();
});
ASSERT_THAT_ERROR(loop.Run().takeError(), Succeeded());
}

TEST_F(JSONRPCTransportTest, ReaderWithUnhandledData) {
std::string message = R"json({"req": "foo")json";
// Write an incomplete message and close the handle.
Expand Down