From: "Toke Høiland-Jørgensen" <toke@toke.dk>
To: Samuel Moelius <sam.moelius@trailofbits.com>
Cc: Samuel Moelius <sam.moelius@trailofbits.com>,
Jamal Hadi Salim <jhs@mojatatu.com>,
Jiri Pirko <jiri@resnulli.us>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
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: Re: [PATCH net v2] net/sched: cake: reject overhead values that underflow length
Date: Wed, 10 Jun 2026 10:06:04 +0200 [thread overview]
Message-ID: <877bo6akgj.fsf@toke.dk> (raw)
In-Reply-To: <20260609232935.1602659.8545fdb04fbe.cake-overhead-underflow@trailofbits.com>
Samuel Moelius <sam.moelius@trailofbits.com> writes:
> 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.
>
> Fixes: a729b7f0bd5b ("sch_cake: Add overhead compensation support to the rate shaper")
> Assisted-by: Codex:gpt-5.5-cyber-preview
> Signed-off-by: Samuel Moelius <sam.moelius@trailofbits.com>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
prev parent reply other threads:[~2026-06-10 8:12 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-09 23:29 [PATCH net v2] net/sched: cake: reject overhead values that underflow length Samuel Moelius
2026-06-10 0:45 ` Jakub Kicinski
2026-06-10 0:55 ` Samuel Moelius
2026-06-10 1:46 ` Jakub Kicinski
2026-06-10 8:06 ` Toke Høiland-Jørgensen [this message]
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