Merge tag 'ipsec-2025-09-22' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

Steffen Klassert says:

====================
pull request (net): ipsec 2025-09-22

1) Fix 0 assignment for SPIs. 0 is not a valid SPI,
   it means no SPI assigned.

2) Fix offloading for inter address family tunnels.

* tag 'ipsec-2025-09-22' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec:
  xfrm: fix offloading of cross-family tunnels
  xfrm: xfrm_alloc_spi shouldn't use 0 as SPI
====================

Link: https://patch.msgid.link/20250922073512.62703-1-steffen.klassert@secunet.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: kuba-moo

net/xfrm/xfrm_device.c

@@ -438,7 +438,7 @@ bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x)
 
 	check_tunnel_size = x->xso.type == XFRM_DEV_OFFLOAD_PACKET &&
 			    x->props.mode == XFRM_MODE_TUNNEL;
-	switch (x->props.family) {
+	switch (x->inner_mode.family) {
 	case AF_INET:
 		/* Check for IPv4 options */
 		if (ip_hdr(skb)->ihl != 5)

net/xfrm/xfrm_state.c

@@ -2583,6 +2583,8 @@ int xfrm_alloc_spi(struct xfrm_state *x, u32 low, u32 high,
 
 	for (h = 0; h < range; h++) {
 		u32 spi = (low == high) ? low : get_random_u32_inclusive(low, high);
+		if (spi == 0)
+			goto next;
 		newspi = htonl(spi);
 
 		spin_lock_bh(&net->xfrm.xfrm_state_lock);
@@ -2598,6 +2600,7 @@ int xfrm_alloc_spi(struct xfrm_state *x, u32 low, u32 high,
 		xfrm_state_put(x0);
 		spin_unlock_bh(&net->xfrm.xfrm_state_lock);
 
+next:
 		if (signal_pending(current)) {
 			err = -ERESTARTSYS;
 			goto unlock;