From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753354AbaIDOLB (ORCPT ); Thu, 4 Sep 2014 10:11:01 -0400 Received: from mail-ie0-f174.google.com ([209.85.223.174]:42565 "EHLO mail-ie0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753284AbaIDOK7 (ORCPT ); Thu, 4 Sep 2014 10:10:59 -0400 Message-ID: <540872E9.7060608@gmail.com> Date: Thu, 04 Sep 2014 10:10:49 -0400 From: Austin S Hemmelgarn User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Andi Kleen , "H. Peter Anvin" CC: Linux Kernel Mailing List , Peter Zijlstra , Ingo Molnar , Thomas Gleixner , Matthew Garrett Subject: Re: RFC: Tainting the kernel on raw I/O access References: <5407863B.9030608@intel.com> <87tx4op8s5.fsf@tassilo.jf.intel.com> In-Reply-To: <87tx4op8s5.fsf@tassilo.jf.intel.com> x-hashcash: 1:21:140904:andi@firstfloor.org::f1cfdc390f46cd5c07789f35e04d583:86af1a882cd78171 x-hashcash: 1:21:140904:h.peter.anvin@intel.com::e791ef77284027e64a092d6f1a383ad0:97283e752719d9c7 x-hashcash: 1:21:140904:linux-kernel@vger.kernel.org::b4904f2e74b80b399460190fc50d6c8c:163f3847b5ca748d x-hashcash: 1:21:140904:peterz@infradead.org::a764587fb76ea148c364be25831f92ee:12d189c35cd684a x-hashcash: 1:21:140904:mingo@kernel.org::6d71744311357a238324b400b4505b25:c260481243277655 x-hashcash: 1:21:140904:tglx@linutronix.de::a65da3d5e8d72edb6e3004a433a78c0:6e5aae856516954 x-hashcash: 1:21:140904:mjg59@srcf.ucam.org::f8e01b894775ad658b10ce61fa8a3087:826de7fc74cfa456 x-stampprotocols: hashcash:1:17;mbound:0:10:3000:5000 Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha1; boundary="------------ms060803080103060907050504" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is a cryptographically signed message in MIME format. --------------ms060803080103060907050504 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 2014-09-03 19:46, Andi Kleen wrote: > "H. Peter Anvin" writes: >=20 >> In a meeting earlier today, we discussed MSR access and that it could = be >> used to do bad things. The same applies to other forms of raw I/O >> (/dev/mem, /dev/port, ioperm, iopl, etc.) >=20 > I don't think it makes sense to use the taint flags as a security > mechanism. They would be a very poor (and likely by itself insecure) on= e. >=20 > As for the original purpose of taints, I'm not aware of any > problems with MSR access or port IO causing excessive=20 > kernel oops reports. Are you? Really? Either one can be used to modify the running kernel (or microcode), and possibly even destroy hardware. Even if it doesn't cause an OOPS or panic, that sounds like something that we should at least taint on. > If there are none I don't think it makes sense. >=20 > At least personally I use MSR accesses quite frequently > for benign purposes. But how much of that is just reading MSR's, and of the writes, how much are either debugging or things that the average user isn't ever going to = do? --------------ms060803080103060907050504 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIFuDCC BbQwggOcoAMCAQICAw9gVDANBgkqhkiG9w0BAQ0FADB5MRAwDgYDVQQKEwdSb290IENBMR4w HAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMTGUNBIENlcnQgU2lnbmlu ZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRAY2FjZXJ0Lm9yZzAeFw0xNDA4 MDgxMTMwNDRaFw0xNTAyMDQxMTMwNDRaMGMxGDAWBgNVBAMTD0NBY2VydCBXb1QgVXNlcjEj MCEGCSqGSIb3DQEJARYUYWhmZXJyb2luN0BnbWFpbC5jb20xIjAgBgkqhkiG9w0BCQEWE2Fo ZW1tZWxnQG9oaW9ndC5jb20wggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQDdmm8R BM5D6fGiB6rpogPZbLYu6CkU6834rcJepfmxKnLarYUYM593/VGygfaaHAyuc8qLaRA3u1M0 Qp29flqmhv1VDTBZ+zFu6JgHjTDniBii1KOZRo0qV3jC5NvaS8KUM67+eQBjm29LhBWVi3+e a8jLxmogFXV0NGej+GHIr5zA9qKz2WJOEoGh0EfqZ2MQTmozcGI43/oqIYhRj8fRMkWXLUAF WsLzPQMpK19hD8fqwlxQWhBV8gsGRG54K5pyaQsjne7m89SF5M8JkNJPH39tHEvfv2Vhf7EM Y4WGyhLAULSlym1AI1uUHR1FfJaj3AChaEJZli/AdajYsqc7AgMBAAGjggFZMIIBVTAMBgNV HRMBAf8EAjAAMFYGCWCGSAGG+EIBDQRJFkdUbyBnZXQgeW91ciBvd24gY2VydGlmaWNhdGUg Zm9yIEZSRUUgaGVhZCBvdmVyIHRvIGh0dHA6Ly93d3cuQ0FjZXJ0Lm9yZzAOBgNVHQ8BAf8E BAMCA6gwQAYDVR0lBDkwNwYIKwYBBQUHAwQGCCsGAQUFBwMCBgorBgEEAYI3CgMEBgorBgEE AYI3CgMDBglghkgBhvhCBAEwMgYIKwYBBQUHAQEEJjAkMCIGCCsGAQUFBzABhhZodHRwOi8v b2NzcC5jYWNlcnQub3JnMDEGA1UdHwQqMCgwJqAkoCKGIGh0dHA6Ly9jcmwuY2FjZXJ0Lm9y Zy9yZXZva2UuY3JsMDQGA1UdEQQtMCuBFGFoZmVycm9pbjdAZ21haWwuY29tgRNhaGVtbWVs Z0BvaGlvZ3QuY29tMA0GCSqGSIb3DQEBDQUAA4ICAQCr4klxcZU/PDRBpUtlb+d6JXl2dfto OUP/6g19dpx6Ekt2pV1eujpIj5whh5KlCSPUgtHZI7BcksLSczQbxNDvRu6LNKqGJGvcp99k cWL1Z6BsgtvxWKkOmy1vB+2aPfDiQQiMCCLAqXwHiNDZhSkwmGsJ7KHMWgF/dRVDnsl6aOQZ jAcBMpUZxzA/bv4nY2PylVdqJWp9N7x86TF9sda1zRZiyUwy83eFTDNzefYPtc4MLppcaD4g Wt8U6T2ffQfCWVzDirhg4WmDH3MybDItjkSB2/+pgGOS4lgtEBMHzAGQqQ+5PojTHRyqu9Jc O59oIGrTaOtKV9nDeDtzNaQZgygJItJi9GoAl68AmIHxpS1rZUNV6X8ydFrEweFdRTVWhUEL 70Cnx84YBojXv01LYBSZaq18K8cERPLaIrUD2go+2ffjdE9ejvYDhNBllY+ufvRizIjQA1uC OdktVAN6auQob94kOOsWpoMSrzHHvOvVW/kbokmKzaLtcs9+nJoL+vPi2AyzbaoQASVZYOGW pE3daA0F5FJfcPZKCwd5wdnmT3dU1IRUxa5vMmgjP20lkfP8tCPtvZv2mmI2Nw5SaXNY4gVu WQrvkV2in+TnGqgEIwUrLVbx9G6PSYZZs07czhO+Q1iVuKdAwjL/AYK0Us9v50acIzbl5CWw ZGj3wjGCA6EwggOdAgEBMIGAMHkxEDAOBgNVBAoTB1Jvb3QgQ0ExHjAcBgNVBAsTFWh0dHA6 Ly93d3cuY2FjZXJ0Lm9yZzEiMCAGA1UEAxMZQ0EgQ2VydCBTaWduaW5nIEF1dGhvcml0eTEh MB8GCSqGSIb3DQEJARYSc3VwcG9ydEBjYWNlcnQub3JnAgMPYFQwCQYFKw4DAhoFAKCCAfUw GAYJKoZIhvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMTQwOTA0MTQxMDQ5 WjAjBgkqhkiG9w0BCQQxFgQU7Vrm86DO4Vu2LYsYmHRXbgBBvhowbAYJKoZIhvcNAQkPMV8w XTALBglghkgBZQMEASowCwYJYIZIAWUDBAECMAoGCCqGSIb3DQMHMA4GCCqGSIb3DQMCAgIA gDANBggqhkiG9w0DAgIBQDAHBgUrDgMCBzANBggqhkiG9w0DAgIBKDCBkQYJKwYBBAGCNxAE MYGDMIGAMHkxEDAOBgNVBAoTB1Jvb3QgQ0ExHjAcBgNVBAsTFWh0dHA6Ly93d3cuY2FjZXJ0 Lm9yZzEiMCAGA1UEAxMZQ0EgQ2VydCBTaWduaW5nIEF1dGhvcml0eTEhMB8GCSqGSIb3DQEJ ARYSc3VwcG9ydEBjYWNlcnQub3JnAgMPYFQwgZMGCyqGSIb3DQEJEAILMYGDoIGAMHkxEDAO BgNVBAoTB1Jvb3QgQ0ExHjAcBgNVBAsTFWh0dHA6Ly93d3cuY2FjZXJ0Lm9yZzEiMCAGA1UE AxMZQ0EgQ2VydCBTaWduaW5nIEF1dGhvcml0eTEhMB8GCSqGSIb3DQEJARYSc3VwcG9ydEBj YWNlcnQub3JnAgMPYFQwDQYJKoZIhvcNAQEBBQAEggEASN7cw/Uwdl9ZTGC8FGUo5nHywdwL 4MyqwIifc1w+jbey47isxSKYfAj9TIfRNjzpe0EW7PrkYJ6HYTeBKSaq3aS3g2RDxdveUXD7 hZnY1WkKO20lMunfcp89yXgxiW19EehpgD0HN3tLnrKNfDfY9HA0C6ZIy0acMUwFjrd/YL0F r3ou8G4ArweR3qcWS3PrMu7Cgl3HncS0DooppQ2seMlCj7MRagiTMxD0sDGJNYdAOaMZwYSp rxhwgnWNKpn1OLfV1pk47ZkkEaUUuHiDD+Nym/f3I4DCv5gmxrOK5Ylt2k54ezOoO/9Tc9Br PCr8zZ7S+UzhF3wdCfOQ8afqnAAAAAAAAA== --------------ms060803080103060907050504--