From: Kees Cook <kees@kernel.org>
To: Gal Pressman <gal@nvidia.com>
Cc: "David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
netdev@vger.kernel.org, Eric Dumazet <edumazet@google.com>,
Paolo Abeni <pabeni@redhat.com>, David Ahern <dsahern@kernel.org>,
Simon Horman <horms@kernel.org>,
linux-hardening@vger.kernel.org, Cosmin Ratiu <cratiu@nvidia.com>
Subject: Re: [PATCH net-next] net: Silence false field-spanning write warning in ip_tunnel_info_opts_set() memcpy
Date: Thu, 9 Jan 2025 08:52:50 -0800 [thread overview]
Message-ID: <202501090852.AA32AF8BD@keescook> (raw)
In-Reply-To: <35791134-6c58-4cc4-a6ab-2965dce9cd4b@nvidia.com>
On Thu, Jan 09, 2025 at 11:00:24AM +0200, Gal Pressman wrote:
> On 08/01/2025 1:28, Kees Cook wrote:
> >> This resolves the following warning:
> >> memcpy: detected field-spanning write (size 8) of single field "_Generic(info, const struct ip_tunnel_info * : ((const void *)((info) + 1)), struct ip_tunnel_info * : ((void *)((info) + 1)) )" at include/net/ip_tunnels.h:662 (size 0)
> >
> > Then you can drop this macro and just use: info->options
> >
> > Looks like you'd need to do it for all the types in struct metadata_dst, but at least you could stop hiding it from the compiler. :)
>
> Can you please explain the "do it for all the types in struct
> metadata_dst" part?
> AFAICT, struct ip_tunnel_info is the only one that's extendable, I don't
> think others need to be modified.
Ah, sorry. If that's the case, then just ip_tunnel_info is fine. (Is all
of the metadata_dst trailing byte allocation logic just for
ip_tunnel_info?)
-Kees
--
Kees Cook
next prev parent reply other threads:[~2025-01-09 16:52 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-07 16:55 [PATCH net-next] net: Silence false field-spanning write warning in ip_tunnel_info_opts_set() memcpy Gal Pressman
2025-01-07 23:28 ` Kees Cook
2025-01-08 6:56 ` Gal Pressman
2025-01-09 9:00 ` Gal Pressman
2025-01-09 16:52 ` Kees Cook [this message]
2025-01-12 6:37 ` Gal Pressman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=202501090852.AA32AF8BD@keescook \
--to=kees@kernel.org \
--cc=cratiu@nvidia.com \
--cc=davem@davemloft.net \
--cc=dsahern@kernel.org \
--cc=edumazet@google.com \
--cc=gal@nvidia.com \
--cc=horms@kernel.org \
--cc=kuba@kernel.org \
--cc=linux-hardening@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.