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 40E3837B03B for ; Thu, 12 Mar 2026 17:28:07 +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=1773336488; cv=none; b=RxVz1nJ3oMMUkoGbmqE6580Kt0zkcOFZzhPJTBAhUVuUyfu0rcMYGFp0CqKxrHWs+CCsGgTWjMeXHSmSgQ+BdmAcjKMb7/nb/+qr0TMrG1/nv49dUkH1Je8P0/wN1njiX+hUwWT4+daK/nRpz2hWa3UdIVDcoNtmO9ec/W4LbFk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773336488; c=relaxed/simple; bh=r4N/H3iHwmT0NdlM6rxKsF1IU1ZtLVPCrOohIaM2NoY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Z4ECFnuP4v8ZN60GvAtM548M+QVh+9+8VoOGO9AC304w0DugGHgLp0U6IapKeX+yuDUXeDPdnQmF2z75ClTdHj89C6NRs9I14GncnzBbyAO7LIRgK01QXEKZFx6Tt7RzKcxXXc8enWZIsttt2p46Z8lsIv0hl32ZL0Pfl+zwri0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=jfBnM8IG; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="jfBnM8IG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 593D3C4CEF7; Thu, 12 Mar 2026 17:28:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1773336487; bh=r4N/H3iHwmT0NdlM6rxKsF1IU1ZtLVPCrOohIaM2NoY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jfBnM8IGE4tDTcOhsuBbbDJ3+2VLJbEgOwiJ7QwQL5du2zfP8ybfi16ajbxhC986Q +X4IvjJmqdRB651v33g7o0BPL+jHQrYgbaHv2k3ouJoO/rQuAMH7Bwmo+Mmx08HKLY ttB0Lp7s9uH98snnf7PA0gM6F0+s0/cRVGDoOygI= Date: Thu, 12 Mar 2026 18:28:02 +0100 From: Greg KH To: Sasha Levin Cc: stable@vger.kernel.org, Victor Nogueira , GangMin Kim , Jamal Hadi Salim , Jakub Kicinski Subject: Re: [PATCH 6.1.y 2/2] net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks Message-ID: <2026031237-blurred-tricolor-b266@gregkh> References: <2026031221-tissue-upgrade-f4d3@gregkh> <20260312171857.1797148-1-sashal@kernel.org> <20260312171857.1797148-2-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260312171857.1797148-2-sashal@kernel.org> On Thu, Mar 12, 2026 at 01:18:57PM -0400, Sasha Levin wrote: > From: Victor Nogueira > > [ Upstream commit 11cb63b0d1a0685e0831ae3c77223e002ef18189 ] > > As Paolo said earlier [1]: > > "Since the blamed commit below, classify can return TC_ACT_CONSUMED while > the current skb being held by the defragmentation engine. As reported by > GangMin Kim, if such packet is that may cause a UaF when the defrag engine > later on tries to tuch again such packet." > > act_ct was never meant to be used in the egress path, however some users > are attaching it to egress today [2]. Attempting to reach a middle > ground, we noticed that, while most qdiscs are not handling > TC_ACT_CONSUMED, clsact/ingress qdiscs are. With that in mind, we > address the issue by only allowing act_ct to bind to clsact/ingress > qdiscs and shared blocks. That way it's still possible to attach act_ct to > egress (albeit only with clsact). > > [1] https://lore.kernel.org/netdev/674b8cbfc385c6f37fb29a1de08d8fe5c2b0fbee.1771321118.git.pabeni@redhat.com/ > [2] https://lore.kernel.org/netdev/cc6bfb4a-4a2b-42d8-b9ce-7ef6644fb22b@ovn.org/ > > Reported-by: GangMin Kim > Fixes: 3f14b377d01d ("net/sched: act_ct: fix skb leak and crash on ooo frags") > CC: stable@vger.kernel.org > Signed-off-by: Victor Nogueira > Acked-by: Jamal Hadi Salim > Link: https://patch.msgid.link/20260225134349.1287037-1-victor@mojatatu.com > Signed-off-by: Jakub Kicinski > Signed-off-by: Sasha Levin > --- > include/net/act_api.h | 1 + > net/sched/act_ct.c | 6 ++++++ > net/sched/cls_api.c | 7 +++++++ > 3 files changed, 14 insertions(+) Ah, it was some trivial fuzz, I've just taken this and not patch 1/2 as that is a new feature not needed here. thanks, greg k-h