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=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 145B4C433DF for ; Tue, 13 Oct 2020 23:52:40 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A9EE121D7B for ; Tue, 13 Oct 2020 23:52:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="u7hD4U1X" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A9EE121D7B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 51D1F6B00CC; Tue, 13 Oct 2020 19:52:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4A5676B00CD; Tue, 13 Oct 2020 19:52:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 346216B00CE; Tue, 13 Oct 2020 19:52:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0129.hostedemail.com [216.40.44.129]) by kanga.kvack.org (Postfix) with ESMTP id 059416B00CC for ; Tue, 13 Oct 2020 19:52:38 -0400 (EDT) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 942F31EE6 for ; Tue, 13 Oct 2020 23:52:38 +0000 (UTC) X-FDA: 77368554396.21.light94_170f59727207 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin21.hostedemail.com (Postfix) with ESMTP id 703AD180442C0 for ; Tue, 13 Oct 2020 23:52:38 +0000 (UTC) X-HE-Tag: light94_170f59727207 X-Filterd-Recvd-Size: 2906 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf03.hostedemail.com (Postfix) with ESMTP for ; Tue, 13 Oct 2020 23:52:38 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (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 A9B7E221FF; Tue, 13 Oct 2020 23:52:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602633157; bh=qpVp/0OIGJrxK5a0RVN5jap1Z1cAf3rg92DMdqS8IuY=; h=Date:From:To:Subject:In-Reply-To:From; b=u7hD4U1XKXDVGTQNEZF/LZq999Bxdag7uK/yKRkr5PHUkbDpYgUsbsYrSeEclAQKU blwRVaIQhUgEVUuFBni54fyl/0HTXmH6fRQGHxk1dEheuNjPsrdeZkdeypm7a0HJzI uuMu+L3369SldZmJ5VY5eiVFaFKhPh1gNF/S6OgU= Date: Tue, 13 Oct 2020 16:52:36 -0700 From: Andrew Morton To: akpm@linux-foundation.org, gustavoars@kernel.org, hannes@cmpxchg.org, linux-mm@kvack.org, mhocko@suse.com, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, vdavydov.dev@gmail.com Subject: [patch 078/181] mm: memcontrol: use flex_array_size() helper in memcpy() Message-ID: <20201013235236.Kk1owSNr4%akpm@linux-foundation.org> In-Reply-To: <20201013164658.3bfd96cc224d8923e66a9f4e@linux-foundation.org> User-Agent: s-nail v14.8.16 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: From: "Gustavo A. R. Silva" Subject: mm: memcontrol: use flex_array_size() helper in memcpy() Make use of the flex_array_size() helper to calculate the size of a flexible array member within an enclosing structure. This helper offers defense-in-depth against potential integer overflows, while at the same time makes it explicitly clear that we are dealing with a flexible array member. Also, remove unnecessary braces. Link: https://lkml.kernel.org/r/ddd60dae2d9aea1ccdd2be66634815c93696125e.1596214831.git.gustavoars@kernel.org Signed-off-by: Gustavo A. R. Silva Acked-by: Michal Hocko Cc: Johannes Weiner Cc: Vladimir Davydov Signed-off-by: Andrew Morton --- mm/memcontrol.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- a/mm/memcontrol.c~mm-memcontrol-use-flex_array_size-helper-in-memcpy +++ a/mm/memcontrol.c @@ -4255,10 +4255,9 @@ static int __mem_cgroup_usage_register_e new->size = size; /* Copy thresholds (if any) to new array */ - if (thresholds->primary) { - memcpy(new->entries, thresholds->primary->entries, (size - 1) * - sizeof(struct mem_cgroup_threshold)); - } + if (thresholds->primary) + memcpy(new->entries, thresholds->primary->entries, + flex_array_size(new, entries, size - 1)); /* Add new threshold */ new->entries[size - 1].eventfd = eventfd; _