nss_slurm - fix file descriptor leaks.

Since this happens inside a the user process, this can inadvertently
cause the user's job to die by running out of file descriptors.

Bug 7814.

Co-authored-by: William Arndt <warndt@lbl.gov>

NEWS

@@ -55,6 +55,7 @@ documents those changes that are of interest to users and administrators.
  -- Fix scancel --full for proctrack/cgroups.
  -- Fix sdiag backfill last and mean queue length stats.
  -- Do not remove batch host when resizing/shrinking a batch job.
+ -- nss_slurm - fix file descriptor leaks.
 * Changes in Slurm 19.05.2
 ==========================

contribs/nss_slurm/libnss_slurm.c

@@ -147,8 +147,9 @@ static struct passwd *_pw_internal(int mode, uid_t uid, const char *name)
 		if (fd < 0)
 			continue;
 
-		if ((pwd = stepd_getpw(fd, stepd->protocol_version,
-				       mode, uid, name)))
+		pwd = stepd_getpw(fd, stepd->protocol_version, mode, uid, name);
+		close(fd);
+		if (pwd)
 			break;
 	}
 	list_iterator_destroy(itr);
@@ -278,8 +279,10 @@ static struct group **_gr_internal(int mode, gid_t uid, const char *name)
 		if (fd < 0)
 			continue;
 
-		if ((grps = stepd_getgr(fd, stepd->protocol_version,
-				        mode, uid, name)))
+		grps = stepd_getgr(fd, stepd->protocol_version, mode, uid,
+				   name);
+		close(fd);
+		if (grps)
 			break;
 	}
 	list_iterator_destroy(itr);