From 257a4b018d1b514a1cc738e3ca11b566d8f3a3d8 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Tue, 26 Dec 2017 17:34:44 +1100 Subject: [PATCH] xfrm: Forbid state updates from changing encap type Currently we allow state updates to competely replace the contents of x->encap. This is bad because on the user side ESP only sets up header lengths depending on encap_type once when the state is first created. This could result in the header lengths getting out of sync with the actual state configuration. In practice key managers will never do a state update to change the encapsulation type. Only the port numbers need to be changed as the peer NAT entry is updated. Therefore this patch adds a check in xfrm_state_update to forbid any changes to the encap_type. Signed-off-by: Herbert Xu Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_state.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c index 500b3391f474..1e80f68e2266 100644 --- a/net/xfrm/xfrm_state.c +++ b/net/xfrm/xfrm_state.c @@ -1534,8 +1534,12 @@ out: err = -EINVAL; spin_lock_bh(&x1->lock); if (likely(x1->km.state == XFRM_STATE_VALID)) { - if (x->encap && x1->encap) + if (x->encap && x1->encap && + x->encap->encap_type == x1->encap->encap_type) memcpy(x1->encap, x->encap, sizeof(*x1->encap)); + else if (x->encap || x1->encap) + goto fail; + if (x->coaddr && x1->coaddr) { memcpy(x1->coaddr, x->coaddr, sizeof(*x1->coaddr)); } @@ -1552,6 +1556,8 @@ out: x->km.state = XFRM_STATE_DEAD; __xfrm_state_put(x); } + +fail: spin_unlock_bh(&x1->lock); xfrm_state_put(x1);