Description of problem:
The Apache module mod_auth_ntlm_winbind allows Apache to perform NTLM 
authentication against Active Directiry. To do this, the module needs to start 
and communicate to ntlm_auth helper program from Samba (same one as Squid 
uses). However, SELinux policy prevents httpd process from starting ntlm_auth. 
The following is logged in Apache error_log:

[Wed Apr 02 19:12:52 2008] [error] [client 192.168.1.81] (13)Permission denied: 
couldn't spawn child ntlm helper process: /usr/bin/ntlm_auth

And the following in audit log:

type=AVC msg=audit(1207152823.277:116711): avc:  denied  { read execute } for  
pid=15152 comm="httpd" name="ntlm_auth" dev=dm-3 ino=54696667 
scontext=root:system_r:httpd_t:s0 
tcontext=system_u:object_r:winbind_helper_exec_t:s0 tclass=file
type=SYSCALL msg=audit(1207152823.277:116711): arch=40000003 syscall=33 
success=no exit=-13 a0=81ee9a08 a1=5 a2=2a01e8 a3=81ee9bf0 items=0 ppid=15148 
pid=15152 auid=0 uid=48 gid=48 euid=48 suid=48 fsuid=48 egid=48 sgid=48 
fsgid=48 tty=(none) comm="httpd" exe="/usr/sbin/httpd" 
subj=root:system_r:httpd_t:s0 key=(null)

Version-Release number of selected component (if applicable):
selinux-policy-2.6.4-70.fc7
selinux-policy-targeted-2.6.4-70.fc7

How reproducible:
Always

Steps to Reproduce:
1. Install mod_auth_ntlm_winbind
2. Configure mod_auth_ntlm_winbind
3. Try to access a location requiring NTLM auth with a browser
  
Additional info:
The following additional SELinux permissions were found to resolve the 
situation:

samba_domtrans_winbind_helper(httpd_t)
allow httpd_t winbind_helper_t:process signal;
apache_append_log(winbind_helper_t)

Maybe this could be enabled via a boolean, or by default.