Description of problem:

radiusd does not work with log file specified by -l option. It is a regression, older version works fine.


Version-Release number of selected component (if applicable):

freeradius-3.0.12-1.el7_3


How reproducible:

100%


Steps to Reproduce:

# ls -l /tmp/radius.log
ls: cannot access /tmp/radius.log: No such file or directory
# radiusd -X -l /tmp/radius.log
radiusd: Cannot change ownership of log file /tmp/radius.log: Operation not permitted
# ls -l /tmp/radius.log
-rw-r-----. 1 root root 3665 Feb 10 10:21 /tmp/radius.log

Workaround is create log file first and then change its ownership to radiusd:radiusd.

# touch /tmp/radius.log
# chown radiusd:radiusd /tmp/radius.log
# radiusd -X -l /tmp/radius.log
^C

It appears that radiusd first creates log file as user who run it, write some messages into the log file, then switch to user and group radiusd and then, tries to change ownership of the log file.

strace output:

...
...
setgroups(1, [95])                      = 0
setgid(95)                              = 0
mkdir("/var/log/radius", 0700)          = -1 EEXIST (File exists)
geteuid()                               = 0
setresuid(4294967295, 95, 0)            = 0
geteuid()                               = 95
setrlimit(RLIMIT_CORE, {rlim_cur=0, rlim_max=0}) = 0
fchown(3, 95, 95)                       = -1 EPERM (Operation not permitted)


Actual results:

radiusd does not work with given log file.


Expected results:

radius works with given log file.