fix MITKRB5-SA-2006-001: multiple local privilege escalation vulnerabilities

fix MITKRB5-SA-2006-001: multiple local privilege escalation vulnerabilities

	* src/appl/gssftp/ftpd/ftpd.c (getdatasock, passive):
	* src/appl/bsd/v4rcp.c (main):
	* src/appl/bsd/krcp.c (main):
	* src/appl/bsd/krshd.c (doit):
	* src/appl/bsd/login.c (main):
	* src/clients/ksu/main.c (sweep_up):
	* src/lib/krb4/kuserok.c (kuserok): Check return values from
	setuid() and related functions to avoid privilege escalation
	vulnerabilities.  Fixes MITKRB5-SA-2006-001. [CVE-2006-3083,
	VU#580124, CVE-2006-3084, VU#401660]

ticket: new
target_version: 1.5.1
tags: pullup

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@18420 dc483132-0cff-0310-8789-dd5450dbe970