Re: [PATCH 3/3] xfrm: clone XFRMA_SEC_CTX during xfrm_do_migrate

[Steffen Klassert <steffen.klassert@secunet.com>]

On Thu, Aug 20, 2020 at 08:16:08PM +0200, Antony Antony wrote:
> XFRMA_SEC_CTX was not cloned from the old to the new.
> Migrate this attribute during XFRMA_MSG_MIGRATE
> 
> Signed-off-by: Antony Antony <antony.antony@secunet.com>
> ---
>  net/xfrm/xfrm_state.c | 28 ++++++++++++++++++++++++++++
>  1 file changed, 28 insertions(+)
> 
> diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
> index 20a12c67a931..dbcb71b800b8 100644
> --- a/net/xfrm/xfrm_state.c
> +++ b/net/xfrm/xfrm_state.c
> @@ -1441,6 +1441,30 @@ int xfrm_state_add(struct xfrm_state *x)
>  EXPORT_SYMBOL(xfrm_state_add);
>  
>  #ifdef CONFIG_XFRM_MIGRATE
> +static inline bool clone_security(struct xfrm_state *x, struct xfrm_sec_ctx *security)
> +{
> +	struct xfrm_user_sec_ctx *uctx;
> +	int size = sizeof(*uctx) + security->ctx_len;
> +	int err;
> +
> +	uctx = kmalloc(size, GFP_KERNEL);
> +	if (!uctx)
> +		return true;
> +
> +	uctx->exttype = XFRMA_SEC_CTX;
> +	uctx->len = size;
> +	uctx->ctx_doi = security->ctx_doi;
> +	uctx->ctx_alg = security->ctx_alg;
> +	uctx->ctx_len = security->ctx_len;
> +	memcpy(uctx + 1, security->ctx_str, security->ctx_len);
> +	err = security_xfrm_state_alloc(x, uctx);
> +	kfree(uctx);
> +	if (err)
> +		return true;

Returning 'true' on memory allocation errors is a bit odd,
please return -ENOMEM instead.