From nobody Sat Apr 11 03:55:25 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F0D31C25B08 for ; Wed, 17 Aug 2022 10:20:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239075AbiHQKU4 (ORCPT ); Wed, 17 Aug 2022 06:20:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55152 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239072AbiHQKUT (ORCPT ); Wed, 17 Aug 2022 06:20:19 -0400 Received: from mail-pg1-x535.google.com (mail-pg1-x535.google.com [IPv6:2607:f8b0:4864:20::535]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BCA4D82F9A for ; Wed, 17 Aug 2022 03:19:51 -0700 (PDT) Received: by mail-pg1-x535.google.com with SMTP id r69so11608286pgr.2 for ; Wed, 17 Aug 2022 03:19:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc; bh=QvbBlM64XGXvCYpSrw2ZhXubC7osA9SaKrvHemruWUk=; b=OH1i67TRQUnuhYunmmI/MYZkQu3kqwPcoWFksU+md4pWKAZnkbL8LMUnQFZcQ2ihXg AXvgKmdFw8N9HiH4T1CGwUKqhKiLDSXrAw1D6savzF8DUwAN1q0NeZNH18ESnyEIQGu6 nugZqGOPIbMKIQDiyvg9qiWA1W+EysZuIoPc58j95+BudKMg4WPJiSVfrxmz36ASlbSh Xd07i+oFEYQ7f2iWznifckbG5x6HlGnLRSUwyz0uFBT2C0TNca2HBDwbWCXuxm3Pel3N uxY6CHinDJ/cnbjrWvKy3JqwZ9dHWsFlPLb2AlhKDtCzlwsdULxFoAWm6UV0hO7fTKtB +wnQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc; bh=QvbBlM64XGXvCYpSrw2ZhXubC7osA9SaKrvHemruWUk=; b=3tCG+cIXVRU3wxG/Kv+vddJwiAzRqCF/Tw6WjShZ6UQySF53lWzYJqAUHtFgECLhDL nz9GSlPsuzIpdYhVwwGkX9z+B/oNYgxshtbUXIYwogGfRq2r67aqADAtFdI0PKnGHfNp lsd4KL9fM4LPBk/oNyA9JDnNk2p9ue4b9GaaJy83Ij+aOYT7FwJPnT4+4367WSY41gtU C0X+VeTkfo+GBKdKFXUiEBAg6cVAtwWrazNlvxjBasPfReJ7oEhwmO4not0gmE9pE0aw SIeju3O07Q1d+aCZRKm+fuzs3ZOH072tO7uuiO1eKOnInYt7XiKMdiDVaCnDikntIsDW ITvw== X-Gm-Message-State: ACgBeo3FLnZR8osYK4UL0r/Dk24dsUqUKupnLKK2vw05NYzB6G1HMiP/ TCI9WuUYr35uhUoi+YuSbTk= X-Google-Smtp-Source: AA6agR5BivBlhg3XB+mK1tMfAb8bN7Obm740H6tldqe9nQKKdLaKub/ufv6AC+sNXwisZ+Ihenb5GA== X-Received: by 2002:a05:6a00:1c53:b0:52d:d673:2241 with SMTP id s19-20020a056a001c5300b0052dd6732241mr24646290pfw.71.1660731590183; Wed, 17 Aug 2022 03:19:50 -0700 (PDT) Received: from hyeyoo.. ([114.29.91.56]) by smtp.gmail.com with ESMTPSA id d8-20020a170903230800b00172633fc236sm1071318plh.174.2022.08.17.03.19.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Aug 2022 03:19:49 -0700 (PDT) From: Hyeonggon Yoo <42.hyeyoo@gmail.com> To: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Vlastimil Babka , Roman Gushchin Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Marco Elver Subject: [PATCH v4 17/17] mm/sl[au]b: check if large object is valid in __ksize() Date: Wed, 17 Aug 2022 19:18:26 +0900 Message-Id: <20220817101826.236819-18-42.hyeyoo@gmail.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220817101826.236819-1-42.hyeyoo@gmail.com> References: <20220817101826.236819-1-42.hyeyoo@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" If address of large object is not beginning of folio or size of the folio is too small, it must be invalid. BUG() in such cases. Cc: Marco Elver Suggested-by: Vlastimil Babka Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Vlastimil Babka --- mm/slab_common.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/mm/slab_common.c b/mm/slab_common.c index 9c273a5fb0d7..98d029212682 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -984,8 +984,11 @@ size_t __ksize(const void *object) =20 folio =3D virt_to_folio(object); =20 - if (unlikely(!folio_test_slab(folio))) + if (unlikely(!folio_test_slab(folio))) { + BUG_ON(folio_size(folio) <=3D KMALLOC_MAX_CACHE_SIZE); + BUG_ON(object !=3D folio_address(folio)); return folio_size(folio); + } =20 return slab_ksize(folio_slab(folio)->slab_cache); } --=20 2.32.0