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 E5D97C43217 for ; Fri, 11 Nov 2022 10:39:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233790AbiKKKjj (ORCPT ); Fri, 11 Nov 2022 05:39:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233358AbiKKKji (ORCPT ); Fri, 11 Nov 2022 05:39:38 -0500 Received: from mail-pg1-x529.google.com (mail-pg1-x529.google.com [IPv6:2607:f8b0:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 707E7654F0 for ; Fri, 11 Nov 2022 02:39:37 -0800 (PST) Received: by mail-pg1-x529.google.com with SMTP id 78so4080993pgb.13 for ; Fri, 11 Nov 2022 02:39:37 -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=g2JUDV1unVlaXbofWs/pNvlYuHbbOkp9TycnqFbOAXE=; b=F+RBn0VN/l/Y5JdSEZ8vZ3ybsM7Js2Nn5c/9xjxvRezBTsc7XxRbmgSuss6c3f3JFU AvqELYzGgFD1+2dTP9v9k9qvY+UDPtlwona1Lz6F0bNcNoBSxE9JbuWaT4TxkwvnZ4ep CT9eGaywFuc1S9zV1Wec4IFXOLBbaE7iV00k8= 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=g2JUDV1unVlaXbofWs/pNvlYuHbbOkp9TycnqFbOAXE=; b=fE2ni/jYRq856JHLyjuQIT6jWJcfSSL74hvzMB9m9cPXO1c3oedAmBWTZC98kUM6a7 51he45NBRDFnxJtEC/msD+p3ASnFVckpmSWI/4e4/Iku2PlNdnOrrBoiJaOrArhx3Hc9 QxjACFGOjzPy1pPbXx1dLv16AyRQS3GwThAouPy2Jk2vEonvg3jHbefFl+RIwpliAHmO qBwn5hSUHc+G6bt4b6VJEq+hilcSm7f+vjOX3SxxOJLMq03RUKctouGkT54P5MQmZi9B 733xM6AcDn9B4XzQba+TeUNIDgBqiGwaZjBftZEi4l9wrf192fjgvj+7Iamc6iZFlt+c L5CQ== X-Gm-Message-State: ANoB5pmFsTOj1wsPTe16rSjC1yR2L1RHmtYNaEIxB/JKH8HrtA+854XK fBgjIyKxiZkVPsAvafH/rMelDw== X-Google-Smtp-Source: AA0mqf7/PaKUrzSWu4IL6ADDSKU5/ZNHIQuZjV3IauWIvRuN5B2UAJJg4qQg3bJ+YQXuRJ3Td6vVJQ== X-Received: by 2002:a63:c146:0:b0:464:a9a6:5717 with SMTP id p6-20020a63c146000000b00464a9a65717mr1036159pgi.584.1668163176947; Fri, 11 Nov 2022 02:39:36 -0800 (PST) Received: from google.com ([240f:75:7537:3187:8d55:c60d:579d:741c]) by smtp.gmail.com with ESMTPSA id s19-20020a634513000000b0046faefad8a1sm1084596pga.79.2022.11.11.02.39.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Nov 2022 02:39:36 -0800 (PST) Date: Fri, 11 Nov 2022 19:39:31 +0900 From: Sergey Senozhatsky To: Kees Cook 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> <202211101904.7A0B0C3@keescook> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <202211101904.7A0B0C3@keescook> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On (22/11/10 19:15), Kees Cook wrote: > On Fri, Nov 11, 2022 at 09:26:31AM +0900, Sergey Senozhatsky wrote: > > On (22/11/10 08:47), coverity-bot wrote: > > > *** CID 1527270: (OVERRUN) > > > drivers/block/zram/zram_drv.c:1727 in zram_recompress() > > > 1721 zstrm = zcomp_stream_get(zram->comps[prio]); > > > 1722 src = kmap_atomic(page); > > > 1723 ret = zcomp_compress(zstrm, src, &comp_len_new); > > > 1724 kunmap_atomic(src); > > > 1725 > > > 1726 if (ret) { > > > 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). > > > > Hmm... I don't really see how prio can evaluate to 4. > > Yeah, I agree. This looks like a false positive. I'm not sure why > Coverity triggered for it. Looking at the extended report, it seems to > not have any idea that prio_max is correctly bounded. > > Sorry for the noise! No worries!