From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:27658 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727151AbfIKIgr (ORCPT ); Wed, 11 Sep 2019 04:36:47 -0400 Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x8B8VcoC132458 for ; Wed, 11 Sep 2019 04:36:45 -0400 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0b-001b2d01.pphosted.com with ESMTP id 2uxunkkqpf-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 11 Sep 2019 04:36:45 -0400 Received: from localhost by e06smtp04.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 11 Sep 2019 09:36:43 +0100 Subject: Re: [PATCH v2] KVM: s390: kvm_s390_vm_start_migration: check dirty_bitmap before using it as target for memset() References: <20190911075218.29153-1-imammedo@redhat.com> From: Janosch Frank Date: Wed, 11 Sep 2019 10:36:38 +0200 MIME-Version: 1.0 In-Reply-To: <20190911075218.29153-1-imammedo@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="vRyjy3CQeEKOH3G9VNNkmYEGONAMZRI1Y" Message-Id: <19baa04d-0d77-7a80-65e2-e00b0d096811@linux.ibm.com> Sender: linux-s390-owner@vger.kernel.org List-ID: To: Igor Mammedov , linux-kernel@vger.kernel.org Cc: borntraeger@de.ibm.com, david@redhat.com, cohuck@redhat.com, heiko.carstens@de.ibm.com, gor@linux.ibm.com, imbrenda@linux.ibm.com, linux-s390@vger.kernel.org, kvm@vger.kernel.org, stable@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --vRyjy3CQeEKOH3G9VNNkmYEGONAMZRI1Y Content-Type: multipart/mixed; boundary="dzBoqpYyJe1rGZE0BD3rqKHntsX41AMyO"; protected-headers="v1" From: Janosch Frank To: Igor Mammedov , linux-kernel@vger.kernel.org Cc: borntraeger@de.ibm.com, david@redhat.com, cohuck@redhat.com, heiko.carstens@de.ibm.com, gor@linux.ibm.com, imbrenda@linux.ibm.com, linux-s390@vger.kernel.org, kvm@vger.kernel.org, stable@vger.kernel.org Message-ID: <19baa04d-0d77-7a80-65e2-e00b0d096811@linux.ibm.com> Subject: Re: [PATCH v2] KVM: s390: kvm_s390_vm_start_migration: check dirty_bitmap before using it as target for memset() References: <20190911075218.29153-1-imammedo@redhat.com> In-Reply-To: <20190911075218.29153-1-imammedo@redhat.com> --dzBoqpYyJe1rGZE0BD3rqKHntsX41AMyO Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 9/11/19 9:52 AM, Igor Mammedov wrote: > If userspace doesn't set KVM_MEM_LOG_DIRTY_PAGES on memslot before call= ing > kvm_s390_vm_start_migration(), kernel will oops with: >=20 > Unable to handle kernel pointer dereference in virtual kernel address= space > Failing address: 0000000000000000 TEID: 0000000000000483 > Fault in home space mode while using kernel ASCE. > AS:0000000002a2000b R2:00000001bff8c00b R3:00000001bff88007 S:0000000= 1bff91000 P:000000000000003d > Oops: 0004 ilc:2 [#1] SMP > ... > Call Trace: > ([<001fffff804ec552>] kvm_s390_vm_set_attr+0x347a/0x3828 [kvm]) > [<001fffff804ecfc0>] kvm_arch_vm_ioctl+0x6c0/0x1998 [kvm] > [<001fffff804b67e4>] kvm_vm_ioctl+0x51c/0x11a8 [kvm] > [<00000000008ba572>] do_vfs_ioctl+0x1d2/0xe58 > [<00000000008bb284>] ksys_ioctl+0x8c/0xb8 > [<00000000008bb2e2>] sys_ioctl+0x32/0x40 > [<000000000175552c>] system_call+0x2b8/0x2d8 > INFO: lockdep is turned off. > Last Breaking-Event-Address: > [<0000000000dbaf60>] __memset+0xc/0xa0 >=20 > due to ms->dirty_bitmap being NULL, which might crash the host. >=20 > Make sure that ms->dirty_bitmap is set before using it or > return -ENIVAL otherwise. Fixed that while picking and added my reviewed-by, as well as the others you removed. Thanks for your patch. --dzBoqpYyJe1rGZE0BD3rqKHntsX41AMyO-- --vRyjy3CQeEKOH3G9VNNkmYEGONAMZRI1Y Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEwGNS88vfc9+v45Yq41TmuOI4ufgFAl14shYACgkQ41TmuOI4 ufhBAhAAoOSaWNtX+nzRWC/HmJHPpeav8+63Qo91vK6EVOpXq/A4mKa1Hcb/IMbg wrXMAxEg3ODpSBTHJzp9t9MjQwdHO8SKfJvcMAJhGHzeEuLycUSBbBdOns1UFwtl xa1Xcxlk3j8jVCqeQZCQHayj2iSKVlCeF6BVhvmtbMjMBwlUdrkjG3Fc1nX0XngU BrE+Of03FCmOe0PBa6OU5IsWyGDb6hO30uY7rdf79jPeb15TQqyEJtzSfoLcc4qh 3+6z9QVmJfC/he2kb7KB7K8KDzBTIp8QQUan4R/XGDKqVGkoIB/WPdkkVXNxoGSf Zy7i531iDZ8eexEwWP2dUSC681r7fermJUS7JWGmvuR15iGhfIvEkliQKG2kmQQ8 U9aeCtrW6hC2/zXbfJ3RZUl4/Km668cUMolgn2lSbta2p2ASsKZ/YsNFkVQYX9t2 cowNHv59ClN87LHRRzQDJj5lUVvncLG8oc7BK9o4Azo3y2iT8Hko7J2TJx1rHXjZ yUgSTsVOVhMXEdcGCmwgIZ964EAW0L2NnqXFrf8qUfo04yMgWwOPbThDYwx2o4XI mT6XsfiqUo+TIrqxJObH9cJEWJHT6ld3+AWqyWuApnZ/11lLT7Ue1Y2PO/xhLhHE qhUXYZgF1gQyRY2N1LD5w+GqZWtclRDf+/hA0d2tJrpzf49dKd4= =6bmL -----END PGP SIGNATURE----- --vRyjy3CQeEKOH3G9VNNkmYEGONAMZRI1Y--