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 B8B4D3C81B9; Mon, 17 Aug 2026 13:55:19 +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=1786974922; cv=none; b=nSggIEyPBsZv4/pU3Pndk5n8MwYVao8Q0F2rw2Xa5TeCd7+Rdz728RPAdRDE+DpXYbLlwkMcB+bu3m/Y+2cYJXpHGkRgTJF4Tvi2/5Gsm4YPDFE9r61fEgw42fBa4zMdd8MXvSCTgAsaMvYc/IeKXlBXGs1jq6ZKWicoKRAzxPc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786974922; c=relaxed/simple; bh=bfnZZ6X6lDpVPBEq3nblQBym91+f6D2VGIKVhmCMapc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=HHYYtaHvpYJOhwjstLajXhh8UhSvc/XiFW4L4tZJXtM3w8vVzTMB/e6o0isyaVO9TFu9O4oEglcdilg2M684XFGOIdsACboNJCnsgMpt+a2H44WfJOdDl18Ui3w/PaZ2onS165W7zY5NqqQ5fre++2IYwmK0fh2R9hbogBG8Ve8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nMhCH1FW; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nMhCH1FW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8C41C1F00A3D; Mon, 17 Aug 2026 13:55:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786974918; bh=9yEErLVcPrQ6TZf2maVlnECFEJ5RXWpExIQ8Bj39Ozg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=nMhCH1FWOArkZtyx0Z1nc/TCm+jnmLZjEue0ZAVmlg0St6aa3Gtt2PLV/G80CbzvL DgagW84yXJD9sGVjdXCeu0CQB5SYWNZAmbYaV0VfhjjjXkPSzzvFr0RmETBUjhcIXc pt9FBIBOwqv5gENRDz4OMc5dr+98eKIez09TIBx8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhiling Zou , Ren Wei , =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.18 072/250] net/sched: sch_cake: drop WARN_ON(1) for malformed packets in ACK filter Date: Mon, 17 Aug 2026 15:30:33 +0200 Message-ID: <20260817132539.386931470@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260817132536.466235697@linuxfoundation.org> References: <20260817132536.466235697@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Toke Høiland-Jørgensen [ Upstream commit 2a33516f9ef59ad11844d4fc152f889449b5daf3 ] The sch_cake ACK filter parses packets to find the TCP header and filter duplicated ACKs if the flow is backlogged. The parsing code contains a WARN_ON(1) which can be triggered by a malformed IP header in certain cases. Depending on the system configuration, this leads either to either spamming dmesg with warnings, or a panic if panic_on_warn is set. The code already correctly skips the offending packet in the branch that triggers the warning, so the WARN_ON itself doesn't really serve any purpose. So just drop it altogether to avoid the inconvenient side effects. Fixes: 8b7138814f29 ("sch_cake: Add optional ACK filter") Reported-by: Zhiling Zou Reported-by: Ren Wei Signed-off-by: Toke Høiland-Jørgensen Link: https://patch.msgid.link/20260729191417.45665-1-toke@toke.dk Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/sched/sch_cake.c | 1 - 1 file changed, 1 deletion(-) diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c index c19eeed7e7cfb..e03fe7096b357 100644 --- a/net/sched/sch_cake.c +++ b/net/sched/sch_cake.c @@ -1268,7 +1268,6 @@ static struct sk_buff *cake_ack_filter(struct cake_sched_data *q, seglen = ntohs(ipv6h_check->payload_len); } else { - WARN_ON(1); /* shouldn't happen */ continue; } -- 2.53.0