From: Aaron Conole <aconole@redhat.com>
To: Kyle Zeng <kylebot@openai.com>
Cc: netdev@vger.kernel.org, Eelco Chaudron <echaudro@redhat.com>,
Ilya Maximets <i.maximets@ovn.org>,
stable@vger.kernel.org
Subject: Re: [PATCH net] openvswitch: fix GSO userspace truncation underflow
Date: Thu, 09 Jul 2026 08:00:04 -0400 [thread overview]
Message-ID: <f7t33xstltn.fsf@redhat.com> (raw)
In-Reply-To: <20260707221635.27489-1-kylebot@openai.com> (Kyle Zeng's message of "Tue, 7 Jul 2026 15:16:35 -0700")
Kyle Zeng <kylebot@openai.com> writes:
> OVS_ACTION_ATTR_TRUNC currently stores a delta from the original skb
> length in OVS_CB(skb)->cutlen. When a later userspace action segments a
> GSO skb, queue_gso_packets() reuses that delta for each smaller segment.
> A segment can then reach queue_userspace_packet() with cutlen greater
> than skb->len, underflowing the length passed to skb_zerocopy().
>
> Store the maximum preserved length instead and bound each consumer
> against the current skb length. Use U32_MAX as the no-truncation
> sentinel so the value remains valid if skb geometry changes before a
> consumer handles it.
>
> Fixes: f2a4d086ed4c ("openvswitch: Add packet truncation support.")
> Cc: stable@vger.kernel.org
> Assisted-by: Codex:gpt-5.5
> Signed-off-by: Kyle Zeng <kylebot@openai.com>
> ---
Reviewed-by: Aaron Conole <aconole@redhat.com>
prev parent reply other threads:[~2026-07-09 12:00 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-07 22:16 [PATCH net] openvswitch: fix GSO userspace truncation underflow Kyle Zeng
2026-07-07 23:16 ` Ilya Maximets
2026-07-09 12:00 ` Aaron Conole [this message]
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