xfrm: policy: check policy direction value

commit 7bab09631c upstream.

The 'dir' parameter in xfrm_migrate() is a user-controlled byte which is used
as an array index. This can lead to an out-of-bound access, kernel lockup and
DoS. Add a check for the 'dir' value.

This fixes CVE-2017-11600.

References: https://bugzilla.redhat.com/show_bug.cgi?id=1474928
Fixes: 80c9abaabf ("[XFRM]: Extension for dynamic update of endpoint address(es)")
Reported-by: "bo Zhang" <zhangbo5891001@gmail.com>
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Vladis Dronov 2017-08-02 19:50:14 +02:00 committed by Greg Kroah-Hartman
parent 31decdcd83
commit 12a70ccaa6
1 changed files with 6 additions and 0 deletions

View File

@ -3308,9 +3308,15 @@ int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
struct xfrm_state *x_new[XFRM_MAX_DEPTH];
struct xfrm_migrate *mp;
/* Stage 0 - sanity checks */
if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
goto out;
if (dir >= XFRM_POLICY_MAX) {
err = -EINVAL;
goto out;
/* Stage 1 - find policy */
if ((pol = xfrm_migrate_policy_find(sel, dir, type, net)) == NULL) {
err = -ENOENT;