From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 E8153403AE0; Wed, 10 Jun 2026 15:09:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781104159; cv=none; b=gSIPy1RtF2eJoMPhZ6xZMuzJ0W/mlJTcLaMDr3/ToNsoy6M+p85Qkh55+++MKCoDDkbCk7nDjpuvTYrFF7YxH79l11oivaaEeQtPvBI40Y7ihz7k+U/FWfX+S9Ume9yWIJaW6NRWo3XE0//Cp/Rp15MZ2eG4tzkaGX+bWAZpxnc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781104159; c=relaxed/simple; bh=tA/untSj+tG9lh2v33r52Qa+XsXymVWnkc/1XyFydK8=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=sHux8lsAHdrlrkgh7UdBYtCHif13XSIGlSpzYxsJYSGqzuNyyplM30lXkdMsr6cWWuNaPoNA7q69Y+8bStJFPGIHVOJfgkMhNDe3HSA7XCOSNSP+dyC7M/Sc1Qk8n1Jnxv/+L0C/ck4LDcev9SnRw1X0t7FVpyC/KjccWn0Hog4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Zm8/SNaX; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Zm8/SNaX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2CA3D1F00893; Wed, 10 Jun 2026 15:09:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1781104158; bh=2riMH4v7nCtM5EEVBOarO8veqFiO7ntvGyqzsKAqWeU=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=Zm8/SNaXaxCusjb4qlDFNpCGen9YFklQkXWpYet1o8XCsSMib5Je9x8JF6qAIRvGz ZN/+sTh8R4VQqqyMdCWPfcXotZduIjxeHKMybZFP0H9RWP2pzyHRmbzbJcaV0oka2I AaW9SIABBO7qa9BkIM5L+xGN1Pb9gM02i5anMRg1V7zDpab6Ahe+bmb3ozSRbQS/kC 7aC5h5JgY4mwWbRtZdi3jo8ZW2bFmUl4IV734AbEGFwi0/vClNpxy38WCa/wrK7qit TFd7X+qPKxGoalpMoixIW1Z2sBUzSOC3x4ecylrgS2BhKWehfRfWSTMQlabv6P+5Um z8lgam4G/f7kA== Date: Wed, 10 Jun 2026 08:09:17 -0700 From: Jakub Kicinski To: Samuel Moelius Cc: Jamal Hadi Salim , Jiri Pirko , "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , netdev@vger.kernel.org (open list:TC subsystem), linux-kernel@vger.kernel.org (open list) Subject: Re: [PATCH] net/sched: act_csum: skip malformed IPv4 headers Message-ID: <20260610080917.52135297@kernel.org> In-Reply-To: <20260605152916.2125473-1-sam.moelius@trailofbits.com> References: <20260605152916.2125473-1-sam.moelius@trailofbits.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Fri, 5 Jun 2026 15:29:15 +0000 Samuel Moelius wrote: > act_csum trusts the IPv4 IHL field before using it to locate transport > header fields. Packets with an invalid short IHL can make the action > write checksum data into the IPv4 header instead of the intended L4 > header. > > The action should not repair or modify packets whose IPv4 header length > is invalid. Treat those packets as not eligible for checksum repair and > leave the configured action result unchanged. I could be wrong but I think we were trying to prevent such packets from getting in rather than fix all the places that call ip_hdr()? Someone please correct me if I'm wrong, or ack this, otherwise I'll toss this patch.. -- pw-bot: reject