From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DD0D0C432C3 for ; Thu, 21 Nov 2019 20:25:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A93002068F for ; Thu, 21 Nov 2019 20:25:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574367919; bh=G/nGSTL1B57XIuGO5ynEHLcReSss6lj0KfyUv9aNKdA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=g9nCUSCad8cgudJ2WCKYUHSYbxlS/4bj6pU6BS1dsz6vN+W/E2K10eYjiFxabNhGK Ji+/mlAwRg1SccNNcaTz8aqnFRKbxS/l1fFqIg2HuJUcUy2H5GBlmNmPPqw2DXZdiv UaXivrpfY/e3MaVE7gQe6GipyI6sPzaOM9v1rXQE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726957AbfKUUZS (ORCPT ); Thu, 21 Nov 2019 15:25:18 -0500 Received: from mail.kernel.org ([198.145.29.99]:53294 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726293AbfKUUZS (ORCPT ); Thu, 21 Nov 2019 15:25:18 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DBADE20643; Thu, 21 Nov 2019 20:25:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574367917; bh=G/nGSTL1B57XIuGO5ynEHLcReSss6lj0KfyUv9aNKdA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Cp0Bp0sUjt8CPblEyVlxHBFiSLOGYda3VM29BL0sfOcMua/LG0WacwAL/nAgTb3k4 zr2liKzh3jH42zJweTi0oxtb0H61H6LHBSbRuL29FxchkMPwWolpl7+2l53MvRNVwd KpvT0gUi5p4Q5tEoRUsVaOm5AW7IrhPhed8pL/tc= Date: Thu, 21 Nov 2019 21:25:14 +0100 From: Greg Kroah-Hartman To: Pavel Machek Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Florian Westphal , Pablo Neira Ayuso , Sasha Levin Subject: Re: [PATCH 4.19 233/422] netfilter: nf_tables: avoid BUG_ON usage Message-ID: <20191121202514.GA812833@kroah.com> References: <20191119051400.261610025@linuxfoundation.org> <20191119051414.205983228@linuxfoundation.org> <20191121201618.GB15106@duo.ucw.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191121201618.GB15106@duo.ucw.cz> User-Agent: Mutt/1.12.2 (2019-09-21) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 21, 2019 at 09:16:18PM +0100, Pavel Machek wrote: > Hi! > > > From: Florian Westphal > > > > [ Upstream commit fa5950e498e7face21a1761f327e6c1152f778c3 ] > > > > None of these spots really needs to crash the kernel. > > In one two cases we can jsut report error to userspace, in the other > > cases we can just use WARN_ON (and leak memory instead). > > Do these conditions trigger for someone, to warrant -stable patch? > > > +++ b/net/netfilter/nft_cmp.c > > @@ -79,7 +79,8 @@ static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr, > > > > err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc, > > tb[NFTA_CMP_DATA]); > > - BUG_ON(err < 0); > > + if (err < 0) > > + return err; > > > > priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]); > > err = nft_validate_register_load(priv->sreg, desc.len); > > @@ -129,7 +130,8 @@ static int nft_cmp_fast_init(const struct nft_ctx *ctx, > > > > err = nft_data_init(NULL, &data, sizeof(data), &desc, > > tb[NFTA_CMP_DATA]); > > - BUG_ON(err < 0); > > + if (err < 0) > > + return err; > > > > priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]); > > err = nft_validate_register_load(priv->sreg, desc.len); > > This goes from "kill kernel with backtrace" to "silently return > failure". Should WARN_ON() be preserved here? if this can be triggered, then the people running with panic-on-warn would reboot. It's best to handle it properly here. And it isn't "silent", the error is returned. thanks, greg k-h