From: Herbert Xu Date: Tue, 26 Dec 2017 06:34:44 +0000 (+1100) Subject: xfrm: Forbid state updates from changing encap type X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=257a4b018d1b514a1cc738e3ca11b566d8f3a3d8;p=linux.git 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 --- diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c index 500b3391f474b..1e80f68e22666 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);