From: Kees Cook <kees@kernel.org>
To: Andrew Lunn <andrew@lunn.ch>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>,
Andrew Lunn <andrew+netdev@lunn.ch>,
Johannes Berg <johannes@sipsolutions.net>,
David Ahern <dsahern@kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-hardening@vger.kernel.org, Simon Horman <horms@kernel.org>
Subject: Re: [PATCH v2 1/4][next] uapi: socket: Introduce struct sockaddr_legacy
Date: Mon, 28 Oct 2024 16:31:08 -0700 [thread overview]
Message-ID: <202410281629.487F7CFE@keescook> (raw)
In-Reply-To: <66641c32-a9fb-4cd6-b910-52d2872fad3d@lunn.ch>
On Mon, Oct 28, 2024 at 09:38:46PM +0100, Andrew Lunn wrote:
> > As this new struct will live in UAPI, to avoid breaking user-space code
> > that expects `struct sockaddr`, the `__kernel_sockaddr_legacy` macro is
> > introduced. This macro allows us to use either `struct sockaddr` or
> > `struct sockaddr_legacy` depending on the context in which the code is
> > used: kernel-space or user-space.
>
> Are there cases of userspace API structures where the flexiable array
> appears in the middle? I assume this new compiler flag is not only for
> use in the kernel? When it gets turned on in user space, will the
> kernel headers will again produce warnings? Should we be considering
> allowing user space to opt in to using sockaddr_legacy?
I expect that the userspace usage of -Wflex-array-member-not-at-end will
be driven by the libc projects, as it'll need to happen there before it
can be done anywhere else. We'll be able to coordinate with them at that
time, but I'm not aware of any plans by any libc to use this flag yet.
--
Kees Cook
next prev parent reply other threads:[~2024-10-28 23:31 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-24 21:07 [PATCH v2 0/4][next] net: Avoid thousands of -Wflex-array-member-not-at-end warnings Gustavo A. R. Silva
2024-10-24 21:11 ` [PATCH v2 1/4][next] uapi: socket: Introduce struct sockaddr_legacy Gustavo A. R. Silva
2024-10-28 20:38 ` Andrew Lunn
2024-10-28 20:47 ` Johannes Berg
2024-10-28 23:40 ` Kees Cook
2024-10-28 23:31 ` Kees Cook [this message]
2024-10-28 23:34 ` Kees Cook
2024-11-01 1:01 ` Jakub Kicinski
2024-11-04 3:43 ` Kees Cook
2024-10-24 21:12 ` [PATCH v2 2/4][next] uapi: wireless: Avoid -Wflex-array-member-not-at-end warnings Gustavo A. R. Silva
2024-10-28 23:35 ` Kees Cook
2024-10-24 21:13 ` [PATCH v2 3/4][next] uapi: net: arp: " Gustavo A. R. Silva
2024-10-28 23:35 ` Kees Cook
2024-10-24 21:14 ` [PATCH v2 4/4][next] uapi: net: " Gustavo A. R. Silva
2024-10-28 23:37 ` Kees Cook
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