util-linux: backport fix for su(1).

Since trusting PAM_RUSER is left to administrators, make sure it can be
trusted if necessary.

srcpkgs/util-linux/patches/0001-lib-pwdutils-don-t-use-getlogin-3.patch

@@ -0,0 +1,47 @@
+From 3386b92e09e8a945cb071808e012e0b600f8bcb2 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?=C3=89rico=20Nogueira?= <erico.erc@gmail.com>
+Date: Tue, 27 Jul 2021 23:41:30 -0300
+Subject: [PATCH 1/4] lib/pwdutils: don't use getlogin(3).
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Per the man page, it shouldn't be used for security purposes. This is an
+issue especially on musl, where getlogin is implemented as
+getenv("LOGNAME"). Since xgetlogin is being used as user identity in su(1), to
+set PAM_RUSER, we simply switch to always using getpwuid(getuid()).
+
+Signed-off-by: Érico Nogueira <erico.erc@gmail.com>
+---
+ lib/pwdutils.c | 8 +++-----
+ 1 file changed, 3 insertions(+), 5 deletions(-)
+
+diff --git a/lib/pwdutils.c b/lib/pwdutils.c
+index d97020cb9..641a9da40 100644
+--- a/lib/pwdutils.c
++++ b/lib/pwdutils.c
+@@ -104,11 +104,6 @@ char *xgetlogin(void)
+ {
+ 	struct passwd *pw = NULL;
+ 	uid_t ruid;
+-	char *user;
+-
+-	user = getlogin();
+-	if (user)
+-		return xstrdup(user);
+ 
+ 	/* GNU Hurd implementation has an extension where a process can exist in a
+ 	 * non-conforming environment, and thus be outside the realms of POSIX
+@@ -117,6 +112,9 @@ char *xgetlogin(void)
+ 	 * environment.
+ 	 *
+ 	 * http://austingroupbugs.net/view.php?id=511
++	 *
++	 * The same implementation is useful for other systems, since getlogin(3)
++	 * shouldn't be used as actual identification.
+ 	 */
+ 	errno = 0;
+ 	ruid = getuid();
+-- 
+2.32.0
+

srcpkgs/util-linux/template

@@ -2,7 +2,7 @@
 # Keep this package sync with util-linux-common
 pkgname=util-linux
 version=2.37.1
-revision=1
+revision=2
 build_style=gnu-configure
 configure_args="--exec-prefix=\${prefix} --enable-libuuid --disable-makeinstall-chown
  --enable-libblkid --enable-fsck --disable-rpath --enable-fs-paths-extra=/usr/sbin:/usr/bin