Subject: Re: [RFC PATCH] xfrm: reduce struct sec_path size

From: Florian Westphal <[email-masked]>
Date: Fri, 6 Feb 2026 01:11:37 +0100

Paolo Abeni <[email-masked]> wrote:
> The mentioned struct has an hole and uses unnecessary wide type to
> store a MAC length.

Good catch.

> struct sec_path {
> 	int                        len;
> 	int                        olen;
> 	struct xfrm_offload        ovec[1];
> 	int                        verified_cnt;

Why not s/int/u8/ while at it?

> 	struct xfrm_state *        xvec[6];

len is xvec, olen is the offload length which can only be 0 or 1 at this time.

verified_cnt also refers to xvec[].

>  	/* Used to keep whole l2 header for transport mode GRO */
> -	__u32			orig_mac_len;
> +	__u16			orig_mac_len;

Matches mac_len in sk_buff; I think this change is fine.