Goal: Input sanitization for chfn and chsh

Fixes: CVE-2011-0721

Status wrt upstream: Already applied upstream (4.1.4.3)

--- a/src/chfn.c
+++ b/src/chfn.c
@@ -551,14 +551,14 @@
 static void check_fields (void)
 {
 	int err;
-	err = valid_field (fullnm, ":,=");
+	err = valid_field (fullnm, ":,=\n");
 	if (err > 0) {
 		fprintf (stderr, _("%s: name with non-ASCII characters: '%s'\n"), Prog, fullnm);
 	} else if (err < 0) {
 		fprintf (stderr, _("%s: invalid name: '%s'\n"), Prog, fullnm);
 		fail_exit (E_NOPERM);
 	}
-	err = valid_field (roomno, ":,=");
+	err = valid_field (roomno, ":,=\n");
 	if (err > 0) {
 		fprintf (stderr, _("%s: room number with non-ASCII characters: '%s'\n"), Prog, roomno);
 	} else if (err < 0) {
@@ -566,17 +566,17 @@
 		         Prog, roomno);
 		fail_exit (E_NOPERM);
 	}
-	if (valid_field (workph, ":,=") != 0) {
+	if (valid_field (workph, ":,=\n") != 0) {
 		fprintf (stderr, _("%s: invalid work phone: '%s'\n"),
 		         Prog, workph);
 		fail_exit (E_NOPERM);
 	}
-	if (valid_field (homeph, ":,=") != 0) {
+	if (valid_field (homeph, ":,=\n") != 0) {
 		fprintf (stderr, _("%s: invalid home phone: '%s'\n"),
 		         Prog, homeph);
 		fail_exit (E_NOPERM);
 	}
-	err = valid_field (slop, ":");
+	err = valid_field (slop, ":\n");
 	if (err > 0) {
 		fprintf (stderr, _("%s: '%s' contains non-ASCII characters\n"), Prog, slop);
 	} else if (err < 0) {
--- a/src/chsh.
+++ b/src/chsh.c
@@ -528,7 +528,7 @@
 	 * users are restricted to using the shells in /etc/shells.
 	 * The shell must be executable by the user.
 	 */
-	if (valid_field (loginsh, ":,=") != 0) {
+	if (valid_field (loginsh, ":,=\n") != 0) {
 		fprintf (stderr, _("%s: Invalid entry: %s\n"), Prog, loginsh);
 		fail_exit (1);
 	}