Lock full after receiving connection from few clients

[mdczaplicki]

I am receiving this error from wolfssl python library.
Am using python 3.6 and this is what I get in console after like 5 clients connect to my socket:

wolfSSL Leaving SendTls13EncryptedExtensions, return -308
wolfSSL error occurred, error = 308 line:7618 file:src/tls13.c
wolfSSL Leaving wolfSSL_negotiate, return -1
wolfSSL Entering SSL_CTX_free
python: ../nptl/pthread_mutex_lock.c:425: __pthread_mutex_lock_full: Assertion `INTERNAL_SYSCALL_ERRNO (e, __err) != ESRCH || !robust' failed.

Is there anything you could help with this? If you need more info, let me know I will anwser.

That's the part of code I am using:

    def __init__(self, host, port):
        self.host = host
        self.port = port
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
        self.sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.sock.setblocking(True)
        self.sock.bind((self.host, self.port))
        self.lock = threading.Lock()

    def listen(self):
        self.sock.listen(10)
        print('Server listening on port', self.sock.getsockname()[1])
        context = wolfssl.SSLContext(wolfssl.PROTOCOL_TLSv1_3, server_side=True)
        context.load_cert_chain(CERTIFICATE, KEY)
        context.verify_mode = wolfssl.CERT_REQUIRED
        context.load_verify_locations(CERTIFICATE)
        try:
            while True:
                new_socket, from_address = self.sock.accept()
                print('Connection address:', from_address)
                new_socket.settimeout(60)
                new_socket.setblocking(True)
                secure_socket = context.wrap_socket(new_socket)
                threading.Thread(target=self.listen_to_client, args=(secure_socket, from_address)).start()
        finally:
            self.sock.close()

[kaleb-himes]

In brief, the problem is caused by repeated locking of a fast mutex, and solved by using a recursive mutex. The default pthread_mutex_t is not recursive. Were you able to resolve this locally? If so, we would welcome a patch via a pull request on the wolfSSL Python solution. If you do decide to open a PR just shoot us an email at [email protected] and we will send over a contributor agreement for review and signing.

Warm Regards,

• K