From 962d3779ef1502ed234baea309cd75b2c1e2353a Mon Sep 17 00:00:00 2001

From: "Andrew G. Morgan" <morgan@kernel.org>

Date: Sat, 27 Nov 2021 21:00:22 -0800

Subject: [PATCH] Complete Linux-PAM compliance for forked child in su and

 login.

As documented here:

http://www.linux-pam.org/Linux-PAM-html/adg-interface-by-app-expected.html#adg-pam_end

The child that is about to exec*() the user shell is supposed to pam_end()

with PAM_DATA_SILENT. This gives the modules a last chance to do a minor

cleanup of the module state before the user's shell is launched.

Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=2037212

Upstream: http://github.com/util-linux/util-linux/commit/4660286e9cdff6d95b49295674b96f83af10ea36

Signed-off-by: Andrew G. Morgan <morgan@kernel.org>

---

 login-utils/login.c     | 3 +++

 login-utils/su-common.c | 3 +++

 2 files changed, 6 insertions(+)

diff --git a/login-utils/login.c b/login-utils/login.c

index 3657f04cd..c62e91e94 100644

--- a/login-utils/login.c

+++ b/login-utils/login.c

@@ -1521,6 +1521,9 @@ int main(int argc, char **argv)

 	child_argv[child_argc++] = NULL;

+	/* http://www.linux-pam.org/Linux-PAM-html/adg-interface-by-app-expected.html#adg-pam_end */

+	(void) pam_end(cxt.pamh, PAM_SUCCESS|PAM_DATA_SILENT);

+

 	execvp(child_argv[0], child_argv + 1);

 	if (!strcmp(child_argv[0], "/bin/sh"))

diff --git a/login-utils/su-common.c b/login-utils/su-common.c

index afd0ea8ad..7d4826bbc 100644

--- a/login-utils/su-common.c

+++ b/login-utils/su-common.c

@@ -1231,6 +1231,9 @@ int su_main(int argc, char **argv, int mode)

 	if (su->simulate_login && chdir(su->pwd->pw_dir) != 0)

 		warn(_("warning: cannot change directory to %s"), su->pwd->pw_dir);

+	/* http://www.linux-pam.org/Linux-PAM-html/adg-interface-by-app-expected.html#adg-pam_end */

+	(void) pam_end(su->pamh, PAM_SUCCESS|PAM_DATA_SILENT);

+

 	if (shell)

 		run_shell(su, shell, command, argv + optind, max(0, argc - optind));

-- 

2.31.1