From 7bab09631c2a303f87a7eb7e3d69e888673b9b7e Mon Sep 17 00:00:00 2001 From: Vladis Dronov Date: Wed, 2 Aug 2017 19:50:14 +0200 Subject: xfrm: policy: check policy direction value 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: 80c9abaabf42 ("[XFRM]: Extension for dynamic update of endpoint address(es)") Cc: # v2.6.21-rc1 Reported-by: "bo Zhang" Signed-off-by: Vladis Dronov Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_policy.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'net/xfrm/xfrm_policy.c') diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index ff61d8557929..6f5a0dad502f 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -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; -- cgit v1.2.3 From 8a4b5784fac2af93ad6a8c08fb56d021e0c0416b Mon Sep 17 00:00:00 2001 From: Lorenzo Colitti Date: Wed, 23 Aug 2017 17:14:39 +0900 Subject: net: xfrm: don't double-hold dst when sk_policy in use. While removing dst_entry garbage collection, commit 52df157f17e5 ("xfrm: take refcnt of dst when creating struct xfrm_dst bundle") changed xfrm_resolve_and_create_bundle so it returns an xdst with a refcount of 1 instead of 0. However, it did not delete the dst_hold performed by xfrm_lookup when a per-socket policy is in use. This means that when a socket policy is in use, dst entries returned by xfrm_lookup have a refcount of 2, and are not freed when no longer in use. Cc: Wei Wang Fixes: 52df157f17 ("xfrm: take refcnt of dst when creating struct xfrm_dst bundle") Tested: https://android-review.googlesource.com/417481 Tested: https://android-review.googlesource.com/418659 Tested: https://android-review.googlesource.com/424463 Tested: https://android-review.googlesource.com/452776 passes on net-next Signed-off-by: Lorenzo Colitti Acked-by: Wei Wang Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_policy.c | 1 - 1 file changed, 1 deletion(-) (limited to 'net/xfrm/xfrm_policy.c') diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index 6f5a0dad502f..69b16ee327d9 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -2226,7 +2226,6 @@ struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig, goto no_transform; } - dst_hold(&xdst->u.dst); route = xdst->route; } } -- cgit v1.2.3