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 80507CDB465 for ; Sun, 15 Oct 2023 02:31:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233420AbjJOCbl (ORCPT ); Sat, 14 Oct 2023 22:31:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43116 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233385AbjJOCbk (ORCPT ); Sat, 14 Oct 2023 22:31:40 -0400 Received: from mail-oo1-xc34.google.com (mail-oo1-xc34.google.com [IPv6:2607:f8b0:4864:20::c34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 364C2D9 for ; Sat, 14 Oct 2023 19:31:39 -0700 (PDT) Received: by mail-oo1-xc34.google.com with SMTP id 006d021491bc7-57b5f0d658dso1968167eaf.0 for ; Sat, 14 Oct 2023 19:31:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1697337098; x=1697941898; darn=vger.kernel.org; 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=w3UcDOTXVnpUdSv4M3bD1yXTstgPxWK1PeD8ZLVfT6g=; b=oY/u8rcl4AHbcP6+ZwJnOKE1gF513xnAESCu4km2p49ybGI9ukmWQkuCriRHzwDpoA ors/XvzLzimX45ywSlKAqR5ylt2uroNyp6vKcAQXMTXvZCWP0G1y/5oA+czSpGmnv60P ngiNh10wGqw4oS+opfyeIitYNZTkzL+eDcLyc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697337098; x=1697941898; 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=w3UcDOTXVnpUdSv4M3bD1yXTstgPxWK1PeD8ZLVfT6g=; b=OgzZABpTzUr74c3HBrUNlH6bKehQG/OsU+0cEXsC3m9kg0+6b2VeFq2lQk+iNmtBY0 RB8e4BJsMegR7g+VozMUlkEC9W29bU71Y4c5+jRJIbMowVZKbZG+5oCM2iY14FC9Auq+ oB2YvoT3BPWx/vBzd1msSvHeX0t8+1EcIelI3tRFnHsFjK8WeH3LI5sLSCRPslg5SPIt pI98T4llZgJ785C8/GYz5rfYnlYyzgiFZ21s4ah9ERxhtdJA6QOAm4addwLd8OAhX21O kHtzsfToYyZIS6jHzAAJpyVLO9+NcWri5z8gFmGVNFMLJGLbOUOxVBAa4Ouqzha+xNIX IECg== X-Gm-Message-State: AOJu0Yx19dgwCNCcYWUWv02HmomUFqDLP6BIiVXCOXUd3xoEzxPTyso5 cDybfiiMgi0WB5BUkAN1FK3LWA== X-Google-Smtp-Source: AGHT+IHHtAlcIGg+Zt50I2CaWbpQ9qgynPGuWlNFgS+CA7bxaLDLrEv2OCfMiEjPuYZ5jDGG/UfOpQ== X-Received: by 2002:a05:6358:5289:b0:13a:4f34:8063 with SMTP id g9-20020a056358528900b0013a4f348063mr33060407rwa.32.1697337098456; Sat, 14 Oct 2023 19:31:38 -0700 (PDT) Received: from www.outflux.net (198-0-35-241-static.hfc.comcastbusiness.net. [198.0.35.241]) by smtp.gmail.com with ESMTPSA id p28-20020aa79e9c000000b006905f6bfc37sm3315559pfq.31.2023.10.14.19.31.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 14 Oct 2023 19:31:37 -0700 (PDT) Date: Sat, 14 Oct 2023 19:31:37 -0700 From: Kees Cook To: Nick Terrell Cc: linux-kernel@vger.kernel.org, Nick Terrell , Kernel Team , Nick Terrell , syzbot+1f2eb3e8cd123ffce499@syzkaller.appspotmail.com, Eric Biggers Subject: Re: [PATCH] zstd: Fix array-index-out-of-bounds UBSAN warning Message-ID: <202310141930.F1F809230@keescook> References: <20231012213428.1390905-1-nickrterrell@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231012213428.1390905-1-nickrterrell@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 12, 2023 at 02:34:28PM -0700, Nick Terrell wrote: > From: Nick Terrell > > Zstd used an array of length 1 to mean a flexible array for C89 > compatibility. Switch to a C99 flexible array to fix the UBSAN warning. > > Tested locally by booting the kernel and writing to and reading from a > BtrFS filesystem with zstd compression enabled. I was unable to reproduce > the issue before the fix, however it is a trivial change. > > Reported-by: syzbot+1f2eb3e8cd123ffce499@syzkaller.appspotmail.com > Reported-by: Eric Biggers > Reported-by: Kees Cook > Signed-off-by: Nick Terrell Thanks! This 1-element conversion doesn't appear to need any sizeof() related changes, so AFAICT this header change is sufficient. Reviewed-by: Kees Cook -- Kees Cook