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);