From: Eric Dumazet <edumazet@google.com>
To: Samuel Moelius <sam.moelius@trailofbits.com>
Cc: "Toke Høiland-Jørgensen" <toke@toke.dk>,
"Jamal Hadi Salim" <jhs@mojatatu.com>,
"Jiri Pirko" <jiri@resnulli.us>,
"David S. Miller" <davem@davemloft.net>,
"Jakub Kicinski" <kuba@kernel.org>,
"Paolo Abeni" <pabeni@redhat.com>,
"Simon Horman" <horms@kernel.org>,
"moderated list:CAKE QDISC" <cake@lists.bufferbloat.net>,
"open list:TC subsystem" <netdev@vger.kernel.org>,
"open list" <linux-kernel@vger.kernel.org>
Subject: [Cake] Re: [PATCH] net/sched: cake: reject overhead values that underflow length
Date: Mon, 8 Jun 2026 18:07:13 -0700 [thread overview]
Message-ID: <CANn89iKCkHBsnvSX3y=_f0UdUXeeh3=WZkWaiRTx1nHEXWkbnA@mail.gmail.com> (raw)
In-Reply-To: <20260609000059.1234072.bc8844db0200.cake-overhead-underflow@trailofbits.com>
On Mon, Jun 8, 2026 at 5:06 PM Samuel Moelius
<sam.moelius@trailofbits.com> wrote:
>
> CAKE accepts overhead values that can make adjusted packet length
> arithmetic underflow. A negative effective length can wrap through
> unsigned arithmetic and become a large value.
>
> Such configurations make rate accounting depend on integer wraparound
> rather than on the packet size userspace intended to model.
>
> Validate overhead settings before using them in adjusted length
> calculations.
>
> Assisted-by: Codex:gpt-5.5-cyber-preview
> Signed-off-by: Samuel Moelius <sam.moelius@trailofbits.com>
> ---
We need a Fixes: tag
pw-bot: cr
prev parent reply other threads:[~2026-06-09 1:07 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-09 0:00 [Cake] [PATCH] net/sched: cake: reject overhead values that underflow length Samuel Moelius
2026-06-09 1:07 ` Eric Dumazet [this message]
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