From: Sabrina Dubroca sd@queasysnail.net
commit 4eb2e13415757a2bce5bb0d580d22bbeef1f5346 upstream.
Xiumei reported a bug with espintcp over IPv6 in transport mode, because xfrm6_transport_finish expects to find IP6CB data (struct inet6_skb_cb). Currently, espintcp zeroes the CB, but the relevant part is actually preserved by previous layers (first set up by tcp, then strparser only zeroes a small part of tcp_skb_tb), so we can just relocate it to the start of skb->cb.
Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Reported-by: Xiumei Mu xmu@redhat.com Signed-off-by: Sabrina Dubroca sd@queasysnail.net Signed-off-by: Steffen Klassert steffen.klassert@secunet.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/xfrm/espintcp.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
--- a/net/xfrm/espintcp.c +++ b/net/xfrm/espintcp.c @@ -29,8 +29,12 @@ static void handle_nonesp(struct espintc
static void handle_esp(struct sk_buff *skb, struct sock *sk) { + struct tcp_skb_cb *tcp_cb = (struct tcp_skb_cb *)skb->cb; + skb_reset_transport_header(skb); - memset(skb->cb, 0, sizeof(skb->cb)); + + /* restore IP CB, we need at least IP6CB->nhoff */ + memmove(skb->cb, &tcp_cb->header, sizeof(tcp_cb->header));
rcu_read_lock(); skb->dev = dev_get_by_index_rcu(sock_net(sk), skb->skb_iif);