Hi!
On 11/11/2026 06:46, Jun Yao wrote:
quoted hunk ↗ jump to hunk
IP-TFS input can be deferred while its reordering queue waits for a missing
sequence number. The VTI receive callback stores a pointer to the tunnel in
skb->cb, and the device can be removed and freed before the callback runs.
Keep only scalar tunnel metadata in an skb extension. The VTI callbacks
look up the device by ifindex under RCU and check its link configuration
before using its private data. If the VTI no longer exists, drop the
deferred packet. Use the same metadata to preserve tunnel mark handling
and IPv6 tunnel detection, and clear it when a new XFRM receive path starts
and after the callback completes.
Signed-off-by: Jun Yao <redacted>
---
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 6787fcf6a..f97412b95 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -5044,6 +5044,7 @@ enum skb_ext_id {
#endif
#ifdef CONFIG_XFRM
SKB_EXT_SEC_PATH,
+ SKB_EXT_XFRM_TUNNEL,
#endif
#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
TC_SKB_EXT,diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 445223a8d..defdd4088 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
[...]
-#define XFRM_TUNNEL_SKB_CB(__skb) ((struct xfrm_tunnel_skb_cb *)&((__skb)->cb[0]))
+static inline struct xfrm_tunnel_info *
+xfrm_tunnel_info_add(struct sk_buff *skb)
+{
+ return skb_ext_add(skb, SKB_EXT_XFRM_TUNNEL);
+}
+
+static inline const struct xfrm_tunnel_info *
+xfrm_tunnel_info(const struct sk_buff *skb)
+{
+ return skb_ext_find(skb, SKB_EXT_XFRM_TUNNEL);
+}
+
+static inline void xfrm_tunnel_info_clear(struct sk_buff *skb)
+{
+ skb_ext_del(skb, SKB_EXT_XFRM_TUNNEL);
+}
The above lines are causing build failures when XFRM is not enabled:
In file included from net/core/sock.c:134:
./include/net/xfrm.h: In function ‘xfrm_tunnel_info_add’:
./include/net/xfrm.h:777:33: error: ‘SKB_EXT_XFRM_TUNNEL’ undeclared (first use in this function); did you mean ‘DST_XFRM_TUNNEL’?
777 | return skb_ext_add(skb, SKB_EXT_XFRM_TUNNEL);
| ^~~~~~~~~~~~~~~~~~~
| DST_XFRM_TUNNEL
./include/net/xfrm.h:777:33: note: each undeclared identifier is reported only once for each function it appears in
./include/net/xfrm.h: In function ‘xfrm_tunnel_info’:
./include/net/xfrm.h:783:34: error: ‘SKB_EXT_XFRM_TUNNEL’ undeclared (first use in this function); did you mean ‘DST_XFRM_TUNNEL’?
783 | return skb_ext_find(skb, SKB_EXT_XFRM_TUNNEL);
| ^~~~~~~~~~~~~~~~~~~
| DST_XFRM_TUNNEL
./include/net/xfrm.h: In function ‘xfrm_tunnel_info_clear’:
./include/net/xfrm.h:788:26: error: ‘SKB_EXT_XFRM_TUNNEL’ undeclared (first use in this function); did you mean ‘DST_XFRM_TUNNEL’?
788 | skb_ext_del(skb, SKB_EXT_XFRM_TUNNEL);
| ^~~~~~~~~~~~~~~~~~~
| DST_XFRM_TUNNEL
---
pw-bot: cr