I have noticed the following issue which began with builds somewhere between 
git master commits bff0a08 and 6173ef7. I did not see this issue with my 
previous builds and haven't been able to pin down the problem, which is why I 
haven't formally filed a bug.

Any help or guidance is appreciated, because this has crippled my use of 
Kamailio.  Only a restart enables it to work again until the issue recurs.

ERROR: tls [tls_server.c:189]: tls_complete_init(): tls: ssl bug #1491 
workaround: not enough memory for safe operation: 8870536
ERROR: <core> [tcp_read.c:1303]: tcp_read_req(): ERROR: tcp_read_req: error 
reading

I currently build against and run openssl-1.0.1k-12.fc22.x86_64.

I have a very small operation and the only change on the operational side is 
that all 5 of my mobile UACs (yes, that's all) have switched from 
CSipSimple/Android to Zoiper/Android, which doesn't yet have support for 
client-side certificates so verify_certificate and require_certificate are off 
for both the server and client config.

The server is started with:
/usr/sbin/kamailio -P /run/kamailio/kamailio.pid -m 64 -M 8

I have tried modifying the shared mem to 128 but the issue still occurs.

Even right now, I am seeing the error when only one UAC has established a TLS 
connection:

# kamcmd tls.list
{
        id: 572
        timeout: 3475
        src_ip: 10.77.79.156
        src_port: 58688
        dst_ip: 10.77.79.3
        dst_port: 5061
        cipher: ECDHE-RSA-RC4-SHA  SSLv3 Kx=ECDH Au=RSA  Enc=RC4(128) Mac=SHA1
        ct_wq_size: 0
        enc_rd_buf: 0
        flags: 2
        state: established
}

# kamailio.cfg
enable_tls=yes
loadmodule "tls.so"
modparam("tls", "connection_timeout", 60)
#modparam("tls", "tls_log", 1)
#modparam("tls", "tls_debug", 1)
#modparam("tls", "low_mem_threshold1", -1)
#modparam("tls", "low_mem_threshold2", 0)
modparam("tls", "session_cache", 1)

# tls.cfg
[server:default]
method = TLSv1+
verify_certificate = no
require_certificate = no
private_key = /etc/kamailio/example.org.key.pem
certificate = /etc/kamailio/example.org.crt.pem
server_name = example.org
cipher_list = ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-
AES128-GCM-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-RSA-RC4-SHA:ECDHE-RSA-AES256-
SHA:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES256-SHA256:DHE-RSA-AES128-GCM-
SHA256:DHE-RSA-AES128-SHA256:DHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA:RC4-
SHA:AES256-GCM-SHA384:AES256-SHA256:CAMELLIA256-SHA:ECDHE-RSA-AES128-
SHA:AES128-GCM-SHA256:AES128-SHA256:AES128-SHA:CAMELLIA128-
SHA:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK

[client:default]
method = TLSv1+
verify_certificate = no
require_certificate = no
private_key = /etc/kamailio/example.org.key.pem
certificate = /etc/kamailio/example.org.crt.pem
cipher_list = ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-
AES128-GCM-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-RSA-RC4-SHA:ECDHE-RSA-AES256-
SHA:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES256-SHA256:DHE-RSA-AES128-GCM-
SHA256:DHE-RSA-AES128-SHA256:DHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA:RC4-
SHA:AES256-GCM-SHA384:AES256-SHA256:CAMELLIA256-SHA:ECDHE-RSA-AES128-
SHA:AES128-GCM-SHA256:AES128-SHA256:AES128-SHA:CAMELLIA128-
SHA:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK

Thanks.  -Anthony