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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1F977C4332F for ; Fri, 11 Nov 2022 00:37:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231824AbiKKAhS (ORCPT ); Thu, 10 Nov 2022 19:37:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56302 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231812AbiKKAhR (ORCPT ); Thu, 10 Nov 2022 19:37:17 -0500 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C358B959C for ; Thu, 10 Nov 2022 16:37:16 -0800 (PST) Received: by mail-pj1-x102c.google.com with SMTP id v4-20020a17090a088400b00212cb0ed97eso3336712pjc.5 for ; Thu, 10 Nov 2022 16:37:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=joENuXZdCD3xg2y3vBRwMSO4BUP9wXySx77lEgOxTdU=; b=Qkd/eDkw5bDGoNk59bjQkjFqB17uANwrULMAAfIyNup6NMRtIdipemKzmdRwlKvc0Y m3gbegXJ41j+KOdrnFkD+PTdQd5lBs9ojFZ8toDmT0YZosaGq+j7kyrCx+8/w/qt7OMq 6pXoyzpiq4fgN8uf0/qpL5mYBi/vgzt6i3+1w= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=joENuXZdCD3xg2y3vBRwMSO4BUP9wXySx77lEgOxTdU=; b=J8c2eFydcp9F1fd6cnmZSmAbuwjjgoQmOUAH1gVCsD+Tr8t+vjNH/cg7Z5QOuVHM4o b9sc2oivRV9eTpoFG9SGKwryC1LgSiXdvxK/fyxM7fvjSg+nwLIfzk4F89paGznDCk8w S5t2JopKAfgmga0GZWM6n2/CVPxekkfcGR+t/p8E86N6ce8AAokhPHHDL0iYpYXsV42S AoNq44+tMaBvbRgoJF/prHug4LUiwS+8eJc/psSKgiK7AANecTd115O0+dOQZRDDDxwQ BHQctmeDBE242ZVoPyVNLPgYWXMYlS9IknBy8lk5LeMrmaP4RhjUzlbJAGResq8MLFiS zbUg== X-Gm-Message-State: ANoB5plotMQd5+toeUOtl+CB4bF82N0LxaCQYaN6PESJ43RqstvTS9ma ZPHCwY7+lfhhnNaxvay2z5LtwA90xFbZJQ== X-Google-Smtp-Source: AA0mqf67I+mNMSyBu5fw9kL7x/lMPOnne39/x2DjuxhKeAAUDDUXN/85avp90U0klAYNieKBXS/LjA== X-Received: by 2002:a17:903:324d:b0:180:4030:1c7d with SMTP id ji13-20020a170903324d00b0018040301c7dmr97707plb.99.1668127036277; Thu, 10 Nov 2022 16:37:16 -0800 (PST) Received: from google.com ([240f:75:7537:3187:8d55:c60d:579d:741c]) by smtp.gmail.com with ESMTPSA id j5-20020a170902c3c500b00186b138706fsm306805plj.13.2022.11.10.16.37.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Nov 2022 16:37:15 -0800 (PST) Date: Fri, 11 Nov 2022 09:37:10 +0900 From: Sergey Senozhatsky To: coverity-bot Cc: Sergey Senozhatsky , Alexey Romanov , linux-kernel@vger.kernel.org, Nick Terrell , Minchan Kim , Suleiman Souhlal , Nitin Gupta , Jens Axboe , Nhat Pham , Andrew Morton , linux-block@vger.kernel.org, "Gustavo A. R. Silva" , linux-next@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: Coverity: zram_recompress(): OVERRUN Message-ID: References: <202211100847.388C61B3@keescook> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <202211100847.388C61B3@keescook> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On (22/11/10 08:47), coverity-bot wrote: [..] > 1704 class_index_old = zs_lookup_class_index(zram->mem_pool, comp_len_old); > 1705 /* > 1706 * Iterate the secondary comp algorithms list (in order of priority) > 1707 * and try to recompress the page. > 1708 */ > 1709 for (; prio < prio_max; prio++) { > vvv CID 1527270: (OVERRUN) > vvv Overrunning array "zram->comps" of 4 8-byte elements at element index 4 (byte offset 39) using index "prio" (which evaluates to 4). > 1710 if (!zram->comps[prio]) > 1711 continue; > 1712 > 1713 /* > 1714 * Skip if the object is already re-compressed with a higher > 1715 * priority algorithm (or same algorithm). prio_max is always limited and max value it can have is 4 (ZRAM_MAX_COMPS). Depending on use case we can limit prio_max even to lower values. So we have for (; prio < 4; prio++) { foo = comps[prio]; } I don't see how prio can be 4 inside of this loop.