pam_filter: Close file after controlling tty

Failing to check the descriptor value meant that there was a bug in the
attempt to close the controlling tty. Moreover, this would lead to a
file descriptor leak as pointed out by the static analyzer tool:

Error: RESOURCE_LEAK (CWE-772): [#def26]
Linux-PAM-1.5.1/modules/pam_filter/pam_filter.c:356: open_fn: Returning handle opened by "open". [Note: The source code implementation of the function has been overridden by a user model.]
Linux-PAM-1.5.1/modules/pam_filter/pam_filter.c:356: var_assign: Assigning: "t" = handle returned from "open("/dev/tty", 2)".
Linux-PAM-1.5.1/modules/pam_filter/pam_filter.c:357: off_by_one: Testing whether handle "t" is strictly greater than zero is suspicious.  "t" leaks when it is zero.
Linux-PAM-1.5.1/modules/pam_filter/pam_filter.c:357: remediation: Did you intend to include equality with zero?
Linux-PAM-1.5.1/modules/pam_filter/pam_filter.c:367: leaked_handle: Handle variable "t" going out of scope leaks the handle.
  365|   		pam_syslog(pamh, LOG_ERR,
  366|   			   "child cannot become new session: %m");
  367|-> 		return PAM_ABORT;
  368|   	    }
  369|

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>

0 files changed, 0 insertions, 0 deletions