[sr-dev] [kamailio/kamailio] Deadlocks after ungracefully terminated TLS connections (#2395)

[Daniel-Constantin Mierla]

I looked at one trace and the blocking leads to the libmysqlclient:

```
#0  0x00007fa250dd3730 in futex_wait (private=<optimized out>, expected=0, futex_word=0x7fa2523a2d1c) at ../sysdeps/unix/sysv/linux/futex-internal.h:61
        __ret = -512
        err = <optimized out>
#1  futex_wait_simple (private=<optimized out>, expected=0, futex_word=0x7fa2523a2d1c) at ../sysdeps/nptl/futex-internal.h:135
No locals.
#2  __pthread_rwlock_wrlock_slow (rwlock=0x7fa2523a2d10) at pthread_rwlock_wrlock.c:67
        waitval = 0
        result = 0
#3  0x00007fa251b11d30 in ?? () from /usr/lib/x86_64-linux-gnu/libmysqlclient.so.20
No symbol table info available.
#4  0x00007fa2510468e7 in CRYPTO_add_lock () from /lib/x86_64-linux-gnu/libcrypto.so.1.0.0
No symbol table info available.
#5  0x00007fa251466cfc in SSL_CTX_free () from /lib/x86_64-linux-gnu/libssl.so.1.0.0
No symbol table info available.
#6  0x00007fa251468ff0 in SSL_free () from /lib/x86_64-linux-gnu/libssl.so.1.0.0
No symbol table info available.
#7  0x00007fa24ef6a38a in tls_h_tcpconn_clean (c=0x7fa2535b8998) at tls_server.c:655
        extra = 0x7fa2535ca9c8
        __func__ = "tls_h_tcpconn_clean"
#8  0x00000000004ed791 in _tcpconn_free (c=0x7fa2535b8998) at core/tcp_main.c:1352
        __func__ = "_tcpconn_free"
#9  0x00000000004ff708 in tcpconn_put_destroy (tcpconn=0x7fa2535b8998) at core/tcp_main.c:3030
        __func__ = "tcpconn_put_destroy"
```

Can you get the output for:

```
ldd /usr/lib/x86_64-linux-gnu/libmysqlclient.so.20
```

There were couple of similar reports for ubuntu 16.04 with security updates, having issues when connecting to mysql server via IP sockets. You can check the latest commits to db_mysql module done in master branch (backported to 5.3, iirc), among them leading to addition of opt_ssl_mode parameter. You can try to connect to mysql via unix socket file, if you have the mysql server on the same system as kamailio (use `localhost` instead of `127.0.0.1` in db url). I spent quite some time analyzing such a similar issue on ubuntu 16.04 with security updates, trying to track changes in libssl/libcrypto and libmysqlclient, but at the end the solution was to upgrade ubuntu not to have a mixture of libraries built with libssl1.0 and couple of them with 1.1.

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/kamailio/kamailio/issues/2395#issuecomment-655003591
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.kamailio.org/pipermail/sr-dev/attachments/20200707/130f4f13/attachment.html>