EC2, Nginx, PHP FPM : Down after 10 minutes up

I’m running a ec2 server (micro instance) with 2 wordpress on it. They were running well months long but since 2 days (after a yum update) PHP-FPM goes down after 10-15 minutes each time I restart it.

Here are my config files

/etc/php-fpm.d/www.conf

[www]
listen = /tmp/php5-fpm.sock
listen.allowed_clients = 127.0.0.1
listen.owner = nginx
listen.group = nginx
listen.mode = 0660
user = apache
group = apache
pm = dynamic
pm.max_children = 10
pm.start_servers = 2
pm.min_spare_servers = 2
pm.max_spare_servers = 10 
pm.max_requests = 50
pm.status_path = /status-oRYJC44bRyXXDrJatf8D
ping.path = /ping-Au9jLCjG6F4NiLQDenbG
slowlog = /var/log/php-fpm/www-slow.log
php_admin_value[error_log] = /var/log/php-fpm/www-error.log
php_admin_flag[log_errors] = on


user nginx;

worker_processes 1;

worker_rlimit_nofile 8192;

events {
    worker_connections 8000;
}

error_log /var/log/nginx/error.log;

pid /var/run/nginx.pid;

http {
    charset utf-8;

    include mime.types;

    default_type application/octet-stream;

    access_log /var/log/nginx/access.log;

    server_tokens off;

    keepalive_timeout 20;

    sendfile on;

    client_max_body_size 32M;

    tcp_nopush on; # off may be better for Comet/long-poll stuff
    tcp_nodelay off; # on may be better for Comet/long-poll stuff

    server_name_in_redirect off;
    types_hash_max_size 2048;

    gzip on;
    gzip_http_version 1.0;
    gzip_comp_level 5;
    gzip_min_length 512;
    gzip_buffers 4 8k;
    gzip_proxied any;
    gzip_types
        text/css
        text/plain
        text/x-component
        application/javascript
        application/json
        application/xml
        application/xhtml+xml
        application/x-font-ttf
        application/x-font-opentype
        application/vnd.ms-fontobject
        image/svg+xml
        image/x-icon;

    gzip_disable "msie6";
    gzip_vary on;

    upstream php {
        server unix:/tmp/php5-fpm.sock;
    }

    include /etc/nginx/conf.d/*.conf;
    include /etc/nginx/sites-enabled/*;
}

The site

server {
        listen 80;
        server_name *.example.com;
        rewrite ^/(.*) http://example.com/$1 permanent;
}
server {
    listen 80 default; ## listen for ipv4; this line is default and implied
    #listen [::]:80 default ipv6only=on; ## listen for ipv6
    listen 443 ssl;
    ssl_certificate     ssl/example.com.crt;
    ssl_certificate_key ssl/example.com.key;    

    # Make site accessible from http://localhost/ or server IP-address
    server_name example.com;
    #server_name_in_redirect off;

    charset utf-8;

    access_log /var/log/nginx/example-access.log;
    error_log /var/log/nginx/example-error.log;

    set $deny_access off;

    if ($uri ~ ^/xmlrpc.php(.*)$ ) {
        set $deny_access on;
    }   

    if ($deny_access = on) {
        return 503;
    } 


    root /usr/share/nginx/example;
    index index.php index.html index.htm;

    location / {
        try_files $uri $uri/ /index.php?$args; 
    }

    location ~ .php$ {
        try_files $uri =404;

        fastcgi_split_path_info ^(.+.php)(/.+)$;
        # NOTE: You should have "cgi.fix_pathinfo = 0;" in php.ini

        fastcgi_pass php;

        fastcgi_index index.php;

        fastcgi_param SCRIPT_FILENAME /usr/share/nginx/example$fastcgi_script_name;
        fastcgi_param DOCUMENT_ROOT /usr/share/nginx/example;

        # send bad requests to 404
        fastcgi_intercept_errors on;

        include fastcgi_params;
    }
}

Here some logs:

PHP FPM:

[11-Jan-2015 19:28:19] NOTICE: ready to handle connections
[11-Jan-2015 19:33:44] WARNING: [pool www] child 5642 exited on signal 11 (SIGSEGV) after 299.891871 seconds from start
[11-Jan-2015 19:33:44] NOTICE: [pool www] child 5662 started

/var/log/messages

Jan 11 19:33:44 domU-12-31-38-04-82-E0 kernel: [6910404.506902] php-fpm[5642]: segfault at 7fce0000000f ip 00007fcedddf6d78 sp 00007fff40e6bd88 error 6 in apc.so[7fceddde9000+23000]