Re: [PATCH iproute2] ip: xfrm: add NUL character to security context name before printing

[Stephen Hemminger]

On Tue, 16 Feb 2021 17:50:58 +0100
Sabrina Dubroca <s...@queasysnail.net> wrote:

> +static void xfrm_sec_ctx_print(FILE *fp, struct rtattr *attr)
> +{
> +     struct xfrm_user_sec_ctx *sctx;
> +     char buf[65536] = {};
> +
> +     fprintf(fp, "\tsecurity context ");
> +
> +     if (RTA_PAYLOAD(attr) < sizeof(*sctx))
> +             fprintf(fp, "(ERROR truncated)");
> +
> +     sctx = RTA_DATA(attr);
> +
> +     memcpy(buf, (char *)(sctx + 1), sctx->ctx_len);
> +     fprintf(fp, "%s %s", buf, _SL_);
> +}

The copy buffer is not needed. Use the printf precision as
a mechanism instead.

         fprintf(fp, "%.*s %s", sctx->ctx_len, (char *)(sctx + 1));