From: Steffen Klassert <steffen.klassert@secunet.com>
To: Charalampos Mitrodimas <charmitro@posteo.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>,
"David S. Miller" <davem@davemloft.net>,
David Ahern <dsahern@kernel.org>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Simon Horman <horms@kernel.org>, <netdev@vger.kernel.org>,
<linux-kernel@vger.kernel.org>,
<syzbot+01b0667934cdceb4451c@syzkaller.appspotmail.com>
Subject: Re: [PATCH ipsec-next v3] net: ipv6: fix field-spanning memcpy warning in AH output
Date: Sun, 17 Aug 2025 16:47:37 +0200 [thread overview]
Message-ID: <aKHriXFxwGlTHwnq@secunet.com> (raw)
In-Reply-To: <20250812-ah6-buffer-overflow-v3-1-446d4340c86f@posteo.net>
On Tue, Aug 12, 2025 at 03:51:25PM +0000, Charalampos Mitrodimas wrote:
> Fix field-spanning memcpy warnings in ah6_output() and
> ah6_output_done() where extension headers are copied to/from IPv6
> address fields, triggering fortify-string warnings about writes beyond
> the 16-byte address fields.
>
> memcpy: detected field-spanning write (size 40) of single field "&top_iph->saddr" at net/ipv6/ah6.c:439 (size 16)
> WARNING: CPU: 0 PID: 8838 at net/ipv6/ah6.c:439 ah6_output+0xe7e/0x14e0 net/ipv6/ah6.c:439
>
> The warnings are false positives as the extension headers are
> intentionally placed after the IPv6 header in memory. Fix by properly
> copying addresses and extension headers separately, and introduce
> helper functions to avoid code duplication.
>
> Reported-by: syzbot+01b0667934cdceb4451c@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=01b0667934cdceb4451c
> Signed-off-by: Charalampos Mitrodimas <charmitro@posteo.net>
Applied, thanks a lot!
prev parent reply other threads:[~2025-08-17 14:47 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-12 15:51 Charalampos Mitrodimas
2025-08-17 14:47 ` Steffen Klassert [this message]
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=aKHriXFxwGlTHwnq@secunet.com \
--to=steffen.klassert@secunet.com \
--cc=charmitro@posteo.net \
--cc=davem@davemloft.net \
--cc=dsahern@kernel.org \
--cc=edumazet@google.com \
--cc=herbert@gondor.apana.org.au \
--cc=horms@kernel.org \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=syzbot+01b0667934cdceb4451c@syzkaller.appspotmail.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®