System.IO.Ports.SerialPort: Under Linux, closing the port while writing cause a deadlock. #100690

Description

If you write from one thread and close the port from another, it is possible for the Write to lockup and never return.
It doesn't repro on Windows.

Reproduction Steps

The following reproduces the issue very quickly.

using System.IO.Ports;

var s = new SerialPort();
s.PortName = args[0];
Console.WriteLine("Using port {0}",s.PortName);

var t = new Thread(() =>
{
    while (true)
    {
        try {
            Console.WriteLine("Say hello");
            s.Write("Hello World");
        } catch (Exception e)
        {}
    }
});
t.Start();

while (true)
{
    s.Open();
    Thread.Sleep(1);
    s.Close();
}

In SerialStreamUnix.cs:
Write eventually calls WriteAsync which queues a SerialStreamWriteRequest then calls EnsureIOLoopRunning.
EnsureIOLoopRunning acquires a lock (_ioLoopLock), however, Dispose does not, stops the ioLoop and writes to _ioLoop.
The IOLoop is stopped, and the request never completes.

Expected behavior

Write should always return or throw.

Actual behavior

it locks up after only a few iteration

Regression?

No response

Known Workarounds

• add lock around Close and Write
• Set a WriteTimeout

Configuration

tested with:
.NET 7.0.17
Linux ARM64

Other information

No response