From: Simon Horman <horms@kernel•org>
To: Kees Cook <keescook@chromium•org>
Cc: Jakub Kicinski <kuba@kernel•org>,
"David S. Miller" <davem@davemloft•net>,
Eric Dumazet <edumazet@google•com>,
Paolo Abeni <pabeni@redhat•com>,
netdev@vger•kernel.org, David Ahern <dsahern@kernel•org>,
Kuniyuki Iwashima <kuniyu@amazon•com>,
Abel Wu <wuyun.abel@bytedance•com>,
Breno Leitao <leitao@debian•org>,
Alexander Mikhalitsyn <alexander@mihalicyn•com>,
David Howells <dhowells@redhat•com>,
linux-kernel@vger•kernel.org, linux-hardening@vger•kernel.org
Subject: Re: [PATCH v3] sock: Use unsafe_memcpy() for sock_copy()
Date: Tue, 5 Mar 2024 13:23:26 +0000 [thread overview]
Message-ID: <20240305132326.GE2357@kernel.org> (raw)
In-Reply-To: <20240304212928.make.772-kees@kernel.org>
On Mon, Mar 04, 2024 at 01:29:31PM -0800, Kees Cook wrote:
> While testing for places where zero-sized destinations were still showing
> up in the kernel, sock_copy() and inet_reqsk_clone() were found, which
> are using very specific memcpy() offsets for both avoiding a portion of
> struct sock, and copying beyond the end of it (since struct sock is really
> just a common header before the protocol-specific allocation). Instead
> of trying to unravel this historical lack of container_of(), just switch
> to unsafe_memcpy(), since that's effectively what was happening already
> (memcpy() wasn't checking 0-sized destinations while the code base was
> being converted away from fake flexible arrays).
>
> Avoid the following false positive warning with future changes to
> CONFIG_FORTIFY_SOURCE:
>
> memcpy: detected field-spanning write (size 3068) of destination "&nsk->__sk_common.skc_dontcopy_end" at net/core/sock.c:2057 (size 0)
>
> Signed-off-by: Kees Cook <keescook@chromium•org>
> ---
> Cc: Jakub Kicinski <kuba@kernel•org>
> Cc: "David S. Miller" <davem@davemloft•net>
> Cc: Eric Dumazet <edumazet@google•com>
> Cc: Paolo Abeni <pabeni@redhat•com>
> Cc: netdev@vger•kernel.org
> v3: fix inet_reqsk_clone() comment
> v2: https://lore.kernel.org/lkml/20240216232220.it.450-kees@kernel.org
> v1: https://lore.kernel.org/lkml/20240216204423.work.066-kees@kernel.org
Reviewed-by: Simon Horman <horms@kernel•org>
next prev parent reply other threads:[~2024-03-05 13:23 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-04 21:29 [PATCH v3] sock: Use unsafe_memcpy() for sock_copy() Kees Cook
2024-03-05 13:23 ` Simon Horman [this message]
2024-03-06 3:10 ` patchwork-bot+netdevbpf
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=20240305132326.GE2357@kernel.org \
--to=horms@kernel$(echo .)org \
--cc=alexander@mihalicyn$(echo .)com \
--cc=davem@davemloft$(echo .)net \
--cc=dhowells@redhat$(echo .)com \
--cc=dsahern@kernel$(echo .)org \
--cc=edumazet@google$(echo .)com \
--cc=keescook@chromium$(echo .)org \
--cc=kuba@kernel$(echo .)org \
--cc=kuniyu@amazon$(echo .)com \
--cc=leitao@debian$(echo .)org \
--cc=linux-hardening@vger$(echo .)kernel.org \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=netdev@vger$(echo .)kernel.org \
--cc=pabeni@redhat$(echo .)com \
--cc=wuyun.abel@bytedance$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox