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 8F2BDC04A95 for ; Sun, 25 Sep 2022 16:44:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229567AbiIYQox (ORCPT ); Sun, 25 Sep 2022 12:44:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34790 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230465AbiIYQow (ORCPT ); Sun, 25 Sep 2022 12:44:52 -0400 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5C46B10FFF; Sun, 25 Sep 2022 09:44:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1664124288; x=1695660288; h=message-id:date:mime-version:subject:to:references:from: in-reply-to:content-transfer-encoding; bh=KY8IHaxepFaMwRh+/xVos1AWOk1yXT54Oq8rCUg0kG4=; b=YVOX87VjfoiCBpY/UJ+1RcnzLoZTQWTMnCRiXkL8gcVGYf8Ue+C36Gly dwxEyUPUE7cBtWdgYUD1iFzjjFSdZo02IydHllrb/b6xTXzLStNmAz9IW /lgaEumtwiCMmkOudKhpg2TARrK+El7LL9YZb1dJUfL3Uf0jBq37jFwcE YdZ9l22A/cN65xdlLoz4amdSu5gN3PXN4qtMhpgfgQt/09o5w4lRTZOyc KuHoSjKuXJvGGLypFShghNYtC12i16ZhrE7v9Eh+RDxNGZ4e++PUuXVk1 xwST1Kb8pHNJC4MNvHRRjRCBVgKZBFSfZSVYx2mKncpWf0OJDZ3PwX4Is A==; X-IronPort-AV: E=McAfee;i="6500,9779,10481"; a="362706373" X-IronPort-AV: E=Sophos;i="5.93,344,1654585200"; d="scan'208";a="362706373" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2022 09:44:47 -0700 X-IronPort-AV: E=Sophos;i="5.93,344,1654585200"; d="scan'208";a="689294159" Received: from obyrd-mobl2.amr.corp.intel.com (HELO [10.212.210.57]) ([10.212.210.57]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2022 09:44:46 -0700 Message-ID: Date: Sun, 25 Sep 2022 09:44:45 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [syzbot] WARNING in __change_page_attr_set_clr Content-Language: en-US To: syzbot , bp@alien8.de, brijesh.singh@amd.com, dan.j.williams@intel.com, dave.hansen@linux.intel.com, hpa@zytor.com, jane.chu@oracle.com, kirill.shutemov@linux.intel.com, linux-kernel@vger.kernel.org, luto@kernel.org, mingo@redhat.com, peterz@infradead.org, seanjc@google.com, syzkaller-bugs@googlegroups.com, tglx@linutronix.de, thomas.lendacky@amd.com, x86@kernel.org, Alexei Starovoitov , Daniel Borkmann , John Fastabend , "open list:BPF (Safe dynamic programs and tools)" References: <00000000000076f3a305e97e9229@google.com> From: Dave Hansen In-Reply-To: <00000000000076f3a305e97e9229@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 9/25/22 04:18, syzbot wrote: > ------------[ cut here ]------------ > CPA refuse W^X violation: 8000000000000163 -> 0000000000000163 range: 0xffffffffa0401000 - 0xffffffffa0401fff PFN 7d8d5 > WARNING: CPU: 0 PID: 3607 at arch/x86/mm/pat/set_memory.c:600 verify_rwx arch/x86/mm/pat/set_memory.c:600 [inline] > WARNING: CPU: 0 PID: 3607 at arch/x86/mm/pat/set_memory.c:600 __change_page_attr arch/x86/mm/pat/set_memory.c:1569 [inline] > WARNING: CPU: 0 PID: 3607 at arch/x86/mm/pat/set_memory.c:600 __change_page_attr_set_clr+0x1f40/0x2020 arch/x86/mm/pat/set_memory.c:1691 > Modules linked in: Yay, one of these that isn't due to wonky 32-bit kernels! This one looks to be naughty intentionally: > void *bpf_jit_alloc_exec_page(void) > { ... > /* Keep image as writeable. The alternative is to keep flipping ro/rw > * every time new program is attached or detached. > */ > set_memory_x((long)image, 1); > return image; > } For STRICT_KERNEL_RWX kernels, I think we would really rather that this code *did* flip ro/rw every time a new BPF program is attached or detached.