selinux: set next pointer before attaching to list

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>

diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index 31b08b3..dc90486 100644 (file)
--- 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;
        }