community/shadow: CVE-2017-2616 regression fix

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

1 files changed, 29 insertions, 0 deletions

diff --git a/community/shadow/303-Reset-pid_child-only-if-waitpid-was-successful.patch b/community/shadow/303-Reset-pid_child-only-if-waitpid-was-successful.patch
new file mode 100644
index 0000000000..64aeb34131
--- /dev/null
+++ b/community/shadow/303-Reset-pid_child-only-if-waitpid-was-successful.patch
@@ -0,0 +1,29 @@
+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);