xfrm: Prevent locally generated packets from direct output in tunnel mode

[ Upstream commit 59630e2ccd ]

Add a check to ensure locally generated packets (skb->sk != NULL) do
not use direct output in tunnel mode, as these packets require proper
L2 header setup that is handled by the normal XFRM processing path.

Fixes: 5eddd76ec2 ("xfrm: fix tunnel mode TX datapath in packet offload mode")
Signed-off-by: Jianbo Liu <jianbol@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Jianbo Liu
2025-10-29 11:50:25 +02:00
committed by Greg Kroah-Hartman
parent 18a9f216d6
commit f15a3d7910

View File

@@ -766,8 +766,12 @@ int xfrm_output(struct sock *sk, struct sk_buff *skb)
/* Exclusive direct xmit for tunnel mode, as
* some filtering or matching rules may apply
* in transport mode.
* Locally generated packets also require
* the normal XFRM path for L2 header setup,
* as the hardware needs the L2 header to match
* for encryption, so skip direct output as well.
*/
if (x->props.mode == XFRM_MODE_TUNNEL)
if (x->props.mode == XFRM_MODE_TUNNEL && !skb->sk)
return xfrm_dev_direct_output(sk, x, skb);
return xfrm_output_resume(sk, skb, 0);