From: Iker Pedrosa <ipedrosa@redhat.com>
Date: Wed, 10 Nov 2021 11:02:04 +0000 (+0100)
Subject: newgrp: fix segmentation fault
X-Git-Tag: 4.10~19^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=497e90751bc0d95cc998b0f06305040563903948;p=thirdparty%2Fshadow.git

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>
---

diff --git a/src/newgrp.c b/src/newgrp.c
index 730f47e8a..566f1c899 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;