Hello,
I have nginx 1.6.2 (compiled from source) and php-fpm 5.5.9 on Ubuntu server 14.04.1 LTS.
I have problem with php-fpm, I receive error 502 Bad Gateway.
In nginx error.log I found this:

2014/11/25 13:13:47 [crit] 5820#0: *29097 connect() to unix:/var/run/php/php5-fpm.sock failed (13: Permission denied) while connecting to upstream, client: 10.10.30.168, server: , request: "GET /index.php HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php5-fpm.sock:", host: "10.10.20.171:59000"


nginx.conf have these settings:

user www-data www-data;

server {
listen 10.10.20.171:59000;
location ~* \.php$ {
fastcgi_index index.php;
fastcgi_pass unix:/var/run/php/php5-fpm.sock;
include fastcgi_params;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
fastcgi_param SCRIPT_NAME $fastcgi_script_name;
}

}

www.conf have these settings:

user = www-data
group = www-data
listen = /var/run/php/php5-fpm.sock
listen.owner = www-data
listen.group = www-data
listen.mode = 0664


Directory /var/run/php/ have www-data owner and these permission:

srw-rw-r-- 1 www-data www-data 0 Nov 25 12:01 php5-fpm.sock



with command "ps aux | grep -F -e php -e nginx" this is the result

root 5818 0.0 0.1 180148 2668 ? Ss 12:01 0:00 nginx: master process /usr/sbin/nginx -c /etc/nginx/nginx.conf
www-data 5819 5.4 4.4 592464 90568 ? Sl 12:01 4:03 nginx: worker process
www-data 5820 6.8 4.9 599712 100984 ? Sl 12:01 5:04 nginx: worker process
www-data 5821 5.4 4.5 595148 92560 ? Sl 12:01 4:02 nginx: worker process
www-data 5822 6.3 4.4 595888 91696 ? Sl 12:01 4:40 nginx: worker process
www-data 5823 0.0 0.3 189044 6724 ? Sl 12:01 0:00 nginx: cache manager process
root 5853 0.0 0.6 133616 12596 ? Ss 12:01 0:00 php-fpm: master process (/etc/php5/fpm/php-fpm.conf)
www-data 5855 0.0 0.1 133616 3720 ? S 12:01 0:00 php-fpm: pool www
www-data 5856 0.0 0.1 133616 3720 ? S 12:01 0:00 php-fpm: pool www
root 28003 0.0 0.0 11748 784 pts/0 R+ 13:15 0:00 grep --color=auto -F -e php -e nginx



Can you help me ?
I need to use socket, not tcp. With tcp all works correctly.

Tnx
Manuel