From 497e90751bc0d95cc998b0f06305040563903948 Mon Sep 17 00:00:00 2001

From: Iker Pedrosa <ipedrosa@redhat.com>

Date: Wed, 10 Nov 2021 12:02:04 +0100

Subject: [PATCH] newgrp: fix segmentation fault

Fix segmentation fault in newgrp when xgetspnam() returns a NULL value

that is immediately freed.

The error was committed in

https://github.com/shadow-maint/shadow/commit/e65cc6aebcb4132fa413f00a905216a5b35b3d57

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2019553

Signed-off-by: Iker Pedrosa <ipedrosa@redhat.com>

---

 src/newgrp.c | 2 +-

 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/newgrp.c b/src/newgrp.c

index 730f47e8..566f1c89 100644

--- a/src/newgrp.c

+++ b/src/newgrp.c

@@ -163,8 +163,8 @@ static void check_perms (const struct group *grp,

 	spwd = xgetspnam (pwd->pw_name);

 	if (NULL != spwd) {

 		pwd->pw_passwd = xstrdup (spwd->sp_pwdp);

+		spw_free (spwd);

 	}

-	spw_free (spwd);

 	if ((pwd->pw_passwd[0] == '\0') && (grp->gr_passwd[0] != '\0')) {

 		needspasswd = true;

-- 

2.31.1