From: Christian Göttsche <cgzones@googlemail.com>
Date: Fri, 18 Aug 2023 15:33:58 +0000 (+0200)
Subject: selinux: set next pointer before attaching to list
X-Git-Tag: v6.4.13~39
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=21cd99431aae3868748c7d9791a14e29103091f8;p=thirdparty%2Fkernel%2Fstable.git

selinux: set next pointer before attaching to list

commit 70d91dc9b2ac91327d0eefd86163abc3548effa6 upstream.

Set the next pointer in filename_trans_read_helper() before attaching
the new node under construction to the list, otherwise garbage would be
dereferenced on subsequent failure during cleanup in the out goto label.

Cc: <stable@vger.kernel.org>
Fixes: 430059024389 ("selinux: implement new format of filename transitions")
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index adcfb63b3550d..6f9ff4643dcbc 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -2005,6 +2005,7 @@ static int filename_trans_read_helper(struct policydb *p, void *fp)
 		if (!datum)
 			goto out;
 
+		datum->next = NULL;
 		*dst = datum;
 
 		/* ebitmap_read() will at least init the bitmap */
@@ -2017,7 +2018,6 @@ static int filename_trans_read_helper(struct policydb *p, void *fp)
 			goto out;
 
 		datum->otype = le32_to_cpu(buf[0]);
-		datum->next = NULL;
 
 		dst = &datum->next;
 	}