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[23.128.96.18]) by mx.google.com with ESMTP id c8si6083878ejr.252.2020.05.17.22.47.51; Sun, 17 May 2020 22:48:14 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=WP9PXV+k; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726545AbgERFqE (ORCPT + 99 others); Mon, 18 May 2020 01:46:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60490 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726040AbgERFqE (ORCPT ); Mon, 18 May 2020 01:46:04 -0400 Received: from mail-ot1-x344.google.com (mail-ot1-x344.google.com [IPv6:2607:f8b0:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E0E3BC061A0C for ; Sun, 17 May 2020 22:46:03 -0700 (PDT) Received: by mail-ot1-x344.google.com with SMTP id h7so98068otr.3 for ; Sun, 17 May 2020 22:46:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=BHIPtwizuJJ8Ut3MjdysZF5NHI8/optEcfuuIjKQd5I=; b=WP9PXV+kr+zcDzjTAYCg1yuLh8csUwd0flQXiXhfhopKRwgBWdvOkZlj7+wMvMgmHX X9395CSLd6Ob1X4+uoIwE+ASm1p8Pzice9ArcCWw21oVk1aIQPGmpHTSGC/azH+TWC8s eAyDXG0zx7Fx/ahE9DDb8zU46xONiX03i0pYL9yopmTPr2GRLreTlJHoib0bT5KL39eI vxeA6Jc506j/inSFcdPonAZlNG/3j2fyFWNavvQ8M9FEwRq6Z2F2WUNN0gNSGbhkJutH EICmG6+A+hvgd6liCOUV66z1VldLaGEBjkIcwzF0otrZ054JXJY6IEblUUTtWStIjcrg ftYg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=BHIPtwizuJJ8Ut3MjdysZF5NHI8/optEcfuuIjKQd5I=; b=R2sSIRjN2gwOzOgWhxEmzrR9HVgGQmei/8dveskVYJO0KmYR24o0LMUqnREmFq4Z6l rih8/b82XO1l3Ui2u4UJedQ4Cu0SRyrCn+k9VVVVVMlaD/C0lHk4Bz4HidrJLYZ5/6x0 BM/PKM+HQAkZ4/Pb5i4m7wBql6FjZdq3wTuUnDR41Hub7xzMyB1Emt+HYsO/RV9+Tu/j txptjaDaLh3bevgdDNr3jQZMRIyjx/pkOnBHeOyyLrU8r80kxbahKwREtiPjqVPARtPx 5Rwi3CApVgFXBMkoUXOoCc45eV6q53uz8RjrYc82PGviK4pZr4PVsrPsaN77veByz12J 9dVQ== X-Gm-Message-State: AOAM533gJn99uPOtJrbh7Bb/8FcySrEloxzmpgZ4FFDM6HLl0IlCVSWq 3xqPFe4CMbq8ffg9U8zH3W7AkcqFe8pw9FAg0f9n5g== X-Received: by 2002:a05:6830:101a:: with SMTP id a26mr10661305otp.53.1589780762697; Sun, 17 May 2020 22:46:02 -0700 (PDT) MIME-Version: 1.0 References: <374485.1589637193@turing-police> In-Reply-To: From: Subhashini Rao Beerisetty Date: Mon, 18 May 2020 11:15:34 +0530 Message-ID: Subject: Re: general protection fault vs Oops To: Cong Wang Cc: Randy Dunlap , =?UTF-8?Q?Valdis_Kl=C4=93tnieks?= , kernelnewbies , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 18, 2020 at 2:16 AM Cong Wang wrote: > > On Sat, May 16, 2020 at 9:16 AM Subhashini Rao Beerisetty > wrote: > > Yes, those are out-of-tree modules. Basically, my question is, in > > general what is the difference between 'general protection fault' and > > 'Oops' failure in kernel mode. > > For your case, they are likely just different consequences of a same > memory error. Let's assume it is a use-after-free, the behavior is UAF > is undefined: If that memory freed by kernel is also unmapped from > kernel address space, you would get a page fault when using it > afterward, that is an Oops. Or if that memory freed by kernel gets > reallocated and remapped as read-only, you would get a general > protection error when you writing to it afterward. Cool, thanks for the clarification.