From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E66042C21E8 for ; Sat, 2 May 2026 18:21:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777746063; cv=none; b=sATxtR4LwHZIkIhG6F/on00l2XzMgYO1Bs6AjQ/NUAArryy0jbtPLV7Z66L4Iim07sxKr4qF0eCMrWP7DTNviB2x+sdHGWI5FamjYMOaVsBVBMc1VGDB2c0IO00paq8CCqDaTOsTfjCfZ/2Bt4qu81FZVz5YPR1gwI/0pwIU5AQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777746063; c=relaxed/simple; bh=vmYZLYzlNJpz/yBVgtgxFm69xbnFtkUKtfURcF4UxRQ=; h=Content-Type:MIME-Version:Subject:From:Message-Id:Date:References: In-Reply-To:To:Cc; b=Svrdogw3UR1k3ltIowb+TAdqOemAX+uTz4j333x/NQyVidg6KEpgbyOcjKj/t0uRNMF3BGWIi/cF17ZVdn6+y2rftbZ7bo53UvWvx3cGY/7w1S/svrzq2nyhsR12HOH/7GMxDf/0jxS+a/Vu8IkIrtkWcOQNzAFf2x/zEH07uIM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LGwfuNLe; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LGwfuNLe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7ECD0C2BCB3; Sat, 2 May 2026 18:21:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777746062; bh=vmYZLYzlNJpz/yBVgtgxFm69xbnFtkUKtfURcF4UxRQ=; h=Subject:From:Date:References:In-Reply-To:To:Cc:From; b=LGwfuNLeYwcCaZKdaZn9WYvN07+sy930cT/ERuBjGJKhbN7QYnGwyQy3IgV94ZhOF nUS06ZI8zNv4OUEYLPdgY//bZofcGIbkJurofb6b6hQU9MN4vZmZS8La9IVYzM3WHx SpbvfaTYolor6ELoUNKFpDr6ce6KHlNrtfw3TKMDrwOwBAzwOgpYQICaG0D6Po4gp+ 2hI9a1cWukmKpfkmQv2GQZTIINLNiuH2mNaEdeoqMhGPEN8VkMmLiVUdgkRiLAtE+q Pxv3wiYhZilB3Nei3LU8a54N53SaJMPVHdY2tZZoXaRuY2CeRkO2Osuyk764LKN5K2 pSb+mqJVCLcpg== Received: from [10.30.226.235] (localhost [IPv6:::1]) by aws-us-west-2-korg-oddjob-rhel9-1.codeaurora.org (Postfix) with ESMTP id 02D44380CEFF; Sat, 2 May 2026 18:20:16 +0000 (UTC) Content-Type: text/plain; charset="utf-8" Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: Re: [PATCH net 0/3] Replace direct dequeue call with qdisc_dequeue_peeked From: patchwork-bot+netdevbpf@kernel.org Message-Id: <177774601480.3903048.13400905631672371303.git-patchwork-notify@kernel.org> Date: Sat, 02 May 2026 18:20:14 +0000 References: <20260430152957.194015-1-jhs@mojatatu.com> In-Reply-To: <20260430152957.194015-1-jhs@mojatatu.com> To: Jamal Hadi Salim Cc: netdev@vger.kernel.org, davem@davemloft.net, kuba@kernel.org, edumazet@google.com, pabeni@redhat.com, horms@kernel.org, jiri@resnulli.us, victor@mojatatu.com, pctammela@mojatatu.com, ghandatmanas@gmail.com, rakshitawasthi17@gmail.com, security@kernel.org Hello: This series was applied to netdev/net.git (main) by Jakub Kicinski : On Thu, 30 Apr 2026 11:29:54 -0400 you wrote: > When sfb and red qdiscs have children (eg qfq qdisc) whose peek() callback is > qdisc_peek_dequeued(), we could get a kernel panic. When the parent of such > qdiscs (eg illustrated in patch #3 as tbf) wants to retrieve an skb from > its child (red/sfb in this case), it will do the following: > 1a. do a peek() - and when sensing there's an skb the child can offer, then > - the child in this case(red/sfb) calls its child's (qfq) peek. > qfq does the right thing and will return the gso_skb queue packet. > Note: if there wasnt a gso_skb entry then qfq will store it there. > 1b. invoke a dequeue() on the child (red/sfb). And herein lies the problem. > - red/sfb will call the child's dequeue() which will essentially just > try to grab something of qfq's queue. > > [...] Here is the summary with links: - [net,1/3] net/sched: sch_red: Replace direct dequeue call with peek and qdisc_dequeue_peeked https://git.kernel.org/netdev/net/c/458d5615272d - [net,2/3] net/sched: sch_sfb: Replace direct dequeue call with peek and qdisc_dequeue_peeked https://git.kernel.org/netdev/net/c/1b9bc71153b0 - [net,3/3] selftests/tc-testing: Add tests that force red and sfb to dequeue from child's gso_skb https://git.kernel.org/netdev/net/c/3a3a30c14d7f You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html