community/shadow: CVE-2017-2616 regression fix

https://lists.debian.org/debian-security-announce/2017/msg00114.html

community/shadow/303-Reset-pid_child-only-if-waitpid-was-successful.patch

+From 7d82f203eeec881c584b2fa06539b39e82985d97 Mon Sep 17 00:00:00 2001
+From: Tobias Stoeckmann <tobias@stoeckmann.org>
+Date: Sun, 14 May 2017 17:58:10 +0200
+Subject: [PATCH] Reset pid_child only if waitpid was successful.
+
+Do not reset the pid_child to 0 if the child process is still
+running. This else-condition can be reached with pid being -1,
+therefore explicitly test this condition.
+
+This is a regression fix for CVE-2017-2616. If su receives a
+signal like SIGTERM, it is not propagated to the child.
+
+Reported-by: Radu Duta <raduduta@gmail.com>
+Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
+---
+ src/su.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/src/su.c
++++ b/src/su.c
+@@ -363,7 +363,7 @@ static void prepare_pam_close_session (v
+ 				/* wake child when resumed */
+ 				kill (pid, SIGCONT);
+ 				stop = false;
+-			} else {
++			} else if (   (pid_t)-1 != pid) {
+ 				pid_child = 0;
+ 			}
+ 		} while (!stop);

community/shadow/APKBUILD

@@ -3,7 +3,7 @@
 # Maintainer: Stuart Cardall <developer@it-offshore.co.uk>
 pkgname=shadow
 pkgver=4.2.1
-pkgrel=10
+pkgrel=11
 pkgdesc="PAM-using login and passwd utilities (usermod, useradd, ...)"
 url="http://pkg-shadow.alioth.debian.org/"
 arch="all"
@@ -18,12 +18,13 @@ source="http://pkg-shadow.alioth.debian.org/releases/shadow-$pkgver.tar.xz
 	verbose-error-when-uid-doesnt-match.patch
 	301-CVE-2017-2616-su-properly-clear-child-PID.patch
 	302-CVE-2016-6252-fix-integer-overflow.patch
+	303-Reset-pid_child-only-if-waitpid-was-successful.patch
 	useradd-usergroups.patch
 	pam-useradd.patch
 	"
 # secfixes:
 #     - CVE-2016-6252
-#     - CVE-2017-2616
+#     - CVE-2017-2616 (+ regression fix)
 
 options="suid"
 builddir="$srcdir/shadow-$pkgver"
@@ -110,5 +111,6 @@ c46760254439176babeef24d93900914092655af3a48f54385adf6ef5a3af76799fb7e96083acd27
 1b3513772a7a0294b587723213e4464cc5a1a42ae6a79e9b9f9ea20083684a21d81e362f44d87ce2e6de2daf396d8422b39019923c0b0cbb44fa4c4c24613c0c  verbose-error-when-uid-doesnt-match.patch
 0954920ce9307948848d8f9ca5ea5bba4db8394793ef314ab5c6770948e96071748192b52ba8c31d543fe71ce0e6e2a7f3a2a92862966a940639a19df1048634  301-CVE-2017-2616-su-properly-clear-child-PID.patch
 36f494347cb980d85ea82331ec620a949be45f5f2c400a3b13f409a8d9c932c0f822cb0baa2ee78c6f356e7bf93de51c1b0f20730e8f3af36a746a5632d19bbe  302-CVE-2016-6252-fix-integer-overflow.patch
+e36d54759b71d48c62aefc4032e63deccafa69d22f8bae772b4c0ca135b431db9cd35a1a2a2adf5c76996e76e13ab82e1cf19bba70c6ca4414b3979a43c292c2  303-Reset-pid_child-only-if-waitpid-was-successful.patch
 49f1d5ded82d2d479805c77d7cc6274c30233596e375b28306b31a33f8fbfc3611dbc77d606081b8300247908c267297dbb6c5d1a30d56095dda53c6a636fb56  useradd-usergroups.patch
 0b4587e263cb6be12fa5ae6bc3b3fc4d3696dae355bc67d085dc58c52ff96edb4d163b95db2092b8c2f3310839430cac03c7af356641b42e24ee4aa6410f5cf1  pam-useradd.patch"