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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id DD66EECAAD8 for ; Thu, 22 Sep 2022 19:40:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3EC42940007; Thu, 22 Sep 2022 15:40:44 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 39B916B0072; Thu, 22 Sep 2022 15:40:44 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 21549940007; Thu, 22 Sep 2022 15:40:44 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 0B1946B0071 for ; Thu, 22 Sep 2022 15:40:44 -0400 (EDT) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id D3F0340E18 for ; Thu, 22 Sep 2022 19:40:43 +0000 (UTC) X-FDA: 79940738766.21.F30CEDF Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf30.hostedemail.com (Postfix) with ESMTP id 5657780006 for ; Thu, 22 Sep 2022 19:40:43 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 585666115C; Thu, 22 Sep 2022 19:40:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 45829C433C1; Thu, 22 Sep 2022 19:40:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663875641; bh=Iu+ioVZAl++oTxE1oI47t/6oQuwifWn8lmpY1yCr8J4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=YC8ixN8EP0aZI0e+nDZs91siEij37VrKEmFWG3Ty2t8usgwjVxksauo5Og7qifkq5 ESf2BqmXtU9USNgh+H2YKJEXRWpyu7EDcgicu3AJOn2B/4WayyL94dp8xbokjZvmw2 M56qmrIx+uvo2sUUrQmzfQ5/ucT/pOiWMPHGNcLJ6IIzRCYzVRcutddcWgSvzdbhZM fcZkJSFboZpZl7fu6RLNBgaLlv3gbFkR4ETLqK750bOZ4J5pst6/eAIZH31PhhVZLn QMHkEcQOXS8pXwYt/LtILex4KMGS/VXDhD7XC9erQbOO/ciNySxRd4PP7XyTR4i5Zs 1sdrT7lGqR5Mw== Date: Thu, 22 Sep 2022 12:40:39 -0700 From: Jakub Kicinski To: Kees Cook Cc: Vlastimil Babka , "David S. Miller" , Eric Dumazet , Paolo Abeni , netdev@vger.kernel.org, Greg Kroah-Hartman , Nick Desaulniers , David Rientjes , Pekka Enberg , Joonsoo Kim , Andrew Morton , Alex Elder , Josef Bacik , David Sterba , Sumit Semwal , Christian =?UTF-8?B?S8O2bmln?= , Jesse Brandeburg , Daniel Micay , Yonghong Song , Marco Elver , Miguel Ojeda , Jacob Shin , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-btrfs@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-fsdevel@vger.kernel.org, intel-wired-lan@lists.osuosl.org, dev@openvswitch.org, x86@kernel.org, linux-wireless@vger.kernel.org, llvm@lists.linux.dev, linux-hardening@vger.kernel.org Subject: Re: [PATCH 02/12] skbuff: Proactively round up to kmalloc bucket size Message-ID: <20220922124039.688be0b8@kernel.org> In-Reply-To: <20220922031013.2150682-3-keescook@chromium.org> References: <20220922031013.2150682-1-keescook@chromium.org> <20220922031013.2150682-3-keescook@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1663875643; a=rsa-sha256; cv=none; b=xEqFm9+vwrjQO2zOA2bzRhZVYnYeTDrMQDj64+a6YdJ/WY/iHuXQ9Ra5/xGwt1Sj9OLSqw e8Bg6gRNTuT0N8jDxM4f1JRB9j8uPEwIW8JDYQpNKFaNYB06aGI/XWhDCFtgX+ueHQhWXi xz5ELCly+ONWfCO6f6c8Jt9Thv9EwSw= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=YC8ixN8E; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf30.hostedemail.com: domain of kuba@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=kuba@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1663875643; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=X/MYTAElgeFQeyyYNMs54J+iDpno7z6oHj6MWUmpCvM=; b=oyQaZC0gd9W2jGPSTM5xmAAC96bJ9FH+v1aMihSuSSuZvAdbAEkn6xUUb7wEwIuHV/pVM1 nZfEn3sM8PQD3ZqHZGRLORjg0iriw7l+xR/s1372WeCqOoKSHSgldlZ8e754SXjLdtOdIn xztjdQOwVg1RoSbQp5rOiwNEEU1pfBU= X-Rspam-User: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 5657780006 Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=YC8ixN8E; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf30.hostedemail.com: domain of kuba@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=kuba@kernel.org X-Stat-Signature: o787esz5fbyqt9kikwywg9ihckcyc7p7 X-HE-Tag: 1663875643-676240 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, 21 Sep 2022 20:10:03 -0700 Kees Cook wrote: > diff --git a/net/core/skbuff.c b/net/core/skbuff.c > index 974bbbbe7138..4fe4c7544c1d 100644 > --- a/net/core/skbuff.c > +++ b/net/core/skbuff.c > @@ -427,14 +427,15 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, > */ > size = SKB_DATA_ALIGN(size); > size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); > - data = kmalloc_reserve(size, gfp_mask, node, &pfmemalloc); > - if (unlikely(!data)) > - goto nodata; > - /* kmalloc(size) might give us more room than requested. > + /* kmalloc(size) might give us more room than requested, so > + * allocate the true bucket size up front. > * Put skb_shared_info exactly at the end of allocated zone, > * to allow max possible filling before reallocation. > */ > - osize = ksize(data); > + osize = kmalloc_size_roundup(size); > + data = kmalloc_reserve(osize, gfp_mask, node, &pfmemalloc); > + if (unlikely(!data)) > + goto nodata; > size = SKB_WITH_OVERHEAD(osize); > prefetchw(data + size); I'd rename osize here to alloc_size for consistency but one could argue either way :) Acked-by: Jakub Kicinski