From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= Subject: Re: [PATCH v4 2/2] xen/blkback: rework connect_ring() to avoid inconsistent xenstore 'ring-page-order' set by malicious blkfront Date: Fri, 11 Jan 2019 15:57:02 +0100 Message-ID: References: <1546839359-5478-1-git-send-email-dongli.zhang@oracle.com> <1546839359-5478-2-git-send-email-dongli.zhang@oracle.com> <20190107120107.euf7mrq7gk6bmibz@mac> <35c7d495-2d6c-5fec-abf8-c5aef55cf866@oracle.com> <56819579-def2-b045-f414-4de45188fe2e@oracle.com> <20190107152708.z4mecdm2apfxz2rk@mac> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from us1-rack-dfw2.inumbo.com ([104.130.134.6]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1ghyFH-0006Wl-H8 for xen-devel@lists.xenproject.org; Fri, 11 Jan 2019 14:57:15 +0000 Received: by mail-ot1-f68.google.com with SMTP id w25so13292705otm.13 for ; Fri, 11 Jan 2019 06:57:14 -0800 (PST) In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" To: Dongli Zhang Cc: axboe@kernel.dk, Konrad Rzeszutek Wilk , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, Paul Durrant , xen-devel , =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= List-Id: xen-devel@lists.xenproject.org T24gVHVlLCBKYW4gOCwgMjAxOSBhdCAxMDo1MyBBTSBEb25nbGkgWmhhbmcgPGRvbmdsaS56aGFu Z0BvcmFjbGUuY29tPiB3cm90ZToKPgo+IEhpIFJvZ2VyLAo+Cj4gT24gMDEvMDcvMjAxOSAxMToy NyBQTSwgUm9nZXIgUGF1IE1vbm7DqSB3cm90ZToKPiA+IE9uIE1vbiwgSmFuIDA3LCAyMDE5IGF0 IDEwOjA3OjM0UE0gKzA4MDAsIERvbmdsaSBaaGFuZyB3cm90ZToKPiA+Pgo+ID4+Cj4gPj4gT24g MDEvMDcvMjAxOSAxMDowNSBQTSwgRG9uZ2xpIFpoYW5nIHdyb3RlOgo+ID4+Pgo+ID4+Pgo+ID4+ PiBPbiAwMS8wNy8yMDE5IDA4OjAxIFBNLCBSb2dlciBQYXUgTW9ubsOpIHdyb3RlOgo+ID4+Pj4g T24gTW9uLCBKYW4gMDcsIDIwMTkgYXQgMDE6MzU6NTlQTSArMDgwMCwgRG9uZ2xpIFpoYW5nIHdy b3RlOgo+ID4+Pj4+IFRoZSB4ZW5zdG9yZSAncmluZy1wYWdlLW9yZGVyJyBpcyB1c2VkIGdsb2Jh bGx5IGZvciBlYWNoIGJsa2JhY2sgcXVldWUgYW5kCj4gPj4+Pj4gdGhlcmVmb3JlIHNob3VsZCBi ZSByZWFkIGZyb20geGVuc3RvcmUgb25seSBvbmNlLiBIb3dldmVyLCBpdCBpcyBvYnRhaW5lZAo+ ID4+Pj4+IGluIHJlYWRfcGVyX3JpbmdfcmVmcygpIHdoaWNoIG1pZ2h0IGJlIGNhbGxlZCBtdWx0 aXBsZSB0aW1lcyBkdXJpbmcgdGhlCj4gPj4+Pj4gaW5pdGlhbGl6YXRpb24gb2YgZWFjaCBibGti YWNrIHF1ZXVlLgo+ID4+Pj4+Cj4gPj4+Pj4gSWYgdGhlIGJsa2Zyb250IGlzIG1hbGljaW91cyBh bmQgdGhlICdyaW5nLXBhZ2Utb3JkZXInIGlzIHNldCBpbiBkaWZmZXJlbnQKPiA+Pj4+PiB2YWx1 ZSBieSBibGtmcm9udCBldmVyeSB0aW1lIGJlZm9yZSBibGtiYWNrIHJlYWRzIGl0LCB0aGlzIG1h eSBlbmQgdXAgYXQKPiA+Pj4+PiB0aGUgIldBUk5fT04oaSAhPSAoWEVOX0JMS0lGX1JFUVNfUEVS X1BBR0UgKiBibGtpZi0+bnJfcmluZ19wYWdlcykpOyIgaW4KPiA+Pj4+PiB4ZW5fYmxraWZfZGlz Y29ubmVjdCgpIHdoZW4gZnJvbnRlbmQgaXMgZGVzdHJveWVkLgo+ID4+Pj4+Cj4gPj4+Pj4gVGhp cyBwYXRjaCByZXdvcmtzIGNvbm5lY3RfcmluZygpIHRvIHJlYWQgeGVuc3RvcmUgJ3JpbmctcGFn ZS1vcmRlcicgb25seQo+ID4+Pj4+IG9uY2UuCj4gPj4+Pj4KPiA+Pj4+PiBTaWduZWQtb2ZmLWJ5 OiBEb25nbGkgWmhhbmcgPGRvbmdsaS56aGFuZ0BvcmFjbGUuY29tPgo+ID4+Pj4+IC0tLQo+ID4+ Pj4+IENoYW5nZWQgc2luY2UgdjE6Cj4gPj4+Pj4gICAqIGNoYW5nZSB0aGUgb3JkZXIgb2YgeGVu c3RvcmUgcmVhZCBpbiByZWFkX3Blcl9yaW5nX3JlZnMKPiA+Pj4+PiAgICogdXNlIHhlbmJ1c19y ZWFkX3Vuc2lnbmVkKCkgaW4gY29ubmVjdF9yaW5nKCkKPiA+Pj4+Pgo+ID4+Pj4+IENoYW5nZWQg c2luY2UgdjI6Cj4gPj4+Pj4gICAqIHNpbXBsaWZ5IHRoZSBjb25kaXRpb24gY2hlY2sgYXMgIihl cnIgIT0gMSAmJiBucl9ncmVmcyA+IDEpIgo+ID4+Pj4+ICAgKiBhdm9pZCBzZXR0aW5nIGVyciBh cyAtRUlOVkFMIHRvIHJlbW92ZSBleHRyYSBvbmUgbGluZSBvZiBjb2RlCj4gPj4+Pj4KPiA+Pj4+ PiBDaGFuZ2VkIHNpbmNlIHYzOgo+ID4+Pj4+ICAgKiBleGl0IGF0IHRoZSBiZWdpbm5pbmcgaWYg IW5yX2dyZWZzCj4gPj4+Pj4gICAqIGNoYW5nZSB0aGUgaWYgc3RhdGVtZW50cyB0byBhdm9pZCB0 ZXN0IChlcnIgIT0gMSkgdHdpY2UKPiA+Pj4+PiAgICogaW5pdGlhbGl6ZSBhICdibGtpZicgc3Rh Y2sgdmFyaWFibGUgKHJlZmVyIHRvIFBBVENIIDEvMikKPiA+Pj4+Pgo+ID4+Pj4+ICBkcml2ZXJz L2Jsb2NrL3hlbi1ibGtiYWNrL3hlbmJ1cy5jIHwgNzYgKysrKysrKysrKysrKysrKysrKysrLS0t LS0tLS0tLS0tLS0tLS0KPiA+Pj4+PiAgMSBmaWxlIGNoYW5nZWQsIDQzIGluc2VydGlvbnMoKyks IDMzIGRlbGV0aW9ucygtKQo+ID4+Pj4+Cj4gPj4+Pj4gZGlmZiAtLWdpdCBhL2RyaXZlcnMvYmxv Y2sveGVuLWJsa2JhY2sveGVuYnVzLmMgYi9kcml2ZXJzL2Jsb2NrL3hlbi1ibGtiYWNrL3hlbmJ1 cy5jCj4gPj4+Pj4gaW5kZXggYTRhYWRhYy4uYTJhY2JjOSAxMDA2NDQKPiA+Pj4+PiAtLS0gYS9k cml2ZXJzL2Jsb2NrL3hlbi1ibGtiYWNrL3hlbmJ1cy5jCj4gPj4+Pj4gKysrIGIvZHJpdmVycy9i bG9jay94ZW4tYmxrYmFjay94ZW5idXMuYwo+ID4+Pj4+IEBAIC05MjYsNyArOTI2LDcgQEAgc3Rh dGljIGludCByZWFkX3Blcl9yaW5nX3JlZnMoc3RydWN0IHhlbl9ibGtpZl9yaW5nICpyaW5nLCBj b25zdCBjaGFyICpkaXIpCj4gPj4+Pj4gICBpbnQgZXJyLCBpLCBqOwo+ID4+Pj4+ICAgc3RydWN0 IHhlbl9ibGtpZiAqYmxraWYgPSByaW5nLT5ibGtpZjsKPiA+Pj4+PiAgIHN0cnVjdCB4ZW5idXNf ZGV2aWNlICpkZXYgPSBibGtpZi0+YmUtPmRldjsKPiA+Pj4+PiAtIHVuc2lnbmVkIGludCByaW5n X3BhZ2Vfb3JkZXIsIG5yX2dyZWZzLCBldnRjaG47Cj4gPj4+Pj4gKyB1bnNpZ25lZCBpbnQgbnJf Z3JlZnMsIGV2dGNobjsKPiA+Pj4+Pgo+ID4+Pj4+ICAgZXJyID0geGVuYnVzX3NjYW5mKFhCVF9O SUwsIGRpciwgImV2ZW50LWNoYW5uZWwiLCAiJXUiLAo+ID4+Pj4+ICAgICAgICAgICAgICAgICAg ICAgJmV2dGNobik7Cj4gPj4+Pj4gQEAgLTkzNiw0MyArOTM2LDM4IEBAIHN0YXRpYyBpbnQgcmVh ZF9wZXJfcmluZ19yZWZzKHN0cnVjdCB4ZW5fYmxraWZfcmluZyAqcmluZywgY29uc3QgY2hhciAq ZGlyKQo+ID4+Pj4+ICAgICAgICAgICByZXR1cm4gZXJyOwo+ID4+Pj4+ICAgfQo+ID4+Pj4+Cj4g Pj4+Pj4gLSBlcnIgPSB4ZW5idXNfc2NhbmYoWEJUX05JTCwgZGV2LT5vdGhlcmVuZCwgInJpbmct cGFnZS1vcmRlciIsICIldSIsCj4gPj4+Pj4gLSAgICAgICAgICAgICAgICAgICAmcmluZ19wYWdl X29yZGVyKTsKPiA+Pj4+PiAtIGlmIChlcnIgIT0gMSkgewo+ID4+Pj4+IC0gICAgICAgICBlcnIg PSB4ZW5idXNfc2NhbmYoWEJUX05JTCwgZGlyLCAicmluZy1yZWYiLCAiJXUiLCAmcmluZ19yZWZb MF0pOwo+ID4+Pj4+ICsgbnJfZ3JlZnMgPSBibGtpZi0+bnJfcmluZ19wYWdlczsKPiA+Pj4+PiAr Cj4gPj4+Pj4gKyBpZiAodW5saWtlbHkoIW5yX2dyZWZzKSkKPiA+Pj4+PiArICAgICAgICAgcmV0 dXJuIC1FSU5WQUw7Cj4gPj4+Pgo+ID4+Pj4gSXMgdGhpcyBldmVuIHBvc3NpYmxlPyBBRkFJQ1Qg cmVhZF9wZXJfcmluZ19yZWZzIHdpbGwgYWx3YXlzIGJlIGNhbGxlZAo+ID4+Pj4gd2l0aCBibGtp Zi0+bnJfcmluZ19wYWdlcyAhPSAwPwo+ID4+Pj4KPiA+Pj4+IElmIHNvLCBJIHdvdWxkIGNvbnNp ZGVyIHR1cm5pbmcgdGhpcyBpbnRvIGEgQlVHX09OL1dBUk5fT04uCj4gPj4+Cj4gPj4+IEl0IHVz ZWQgdG8gYmUgIldBUk5fT04oIW5yX2dyZWZzKTsiIGluIHRoZSB2MyBvZiB0aGUgcGF0Y2guCj4g Pj4+Cj4gPj4+IEkgd291bGQgdHVybiBpdCBpbnRvIFdBUk5fT04gaWYgaXQgaXMgZmluZSB3aXRo IGJvdGggUGF1bCBhbmQgeW91Lgo+ID4+Cj4gPj4gVG8gY2xhcmlmeSwgSSB3b3VsZCB1c2UgV0FS Tl9PTigpIGJlZm9yZSBleGl0IHdpdGggLUVJTlZBTCAod2hlbgo+ID4+IGJsa2lmLT5ucl9yaW5n X3BhZ2VzIGlzIDApLgo+ID4KPiA+IEdpdmVuIHRoYXQgdGhpcyBmdW5jdGlvbiB3aWxsIG5ldmVy IGJlIGNhbGxlZCB3aXRoIG5yX3JpbmdfcGFnZXMgPT0gMAo+ID4gSSB3b3VsZCBiZSBmaW5lIHdp dGgganVzdCB1c2luZyBhIEJVR19PTiwgZ2V0dGluZyBoZXJlIHdpdGgKPiA+IG5yX3JpbmdfcGFn ZXMgPT0gMCB3b3VsZCBpbXBseSBtZW1vcnkgY29ycnVwdGlvbiBvciBzb21lIG90aGVyIHNldmVy ZQo+ID4gaXNzdWUgaGFzIGhhcHBlbmVkLCBhbmQgdGhlcmUncyBubyBwb3NzaWJsZSByZWNvdmVy eS4KPiA+Cj4gPiBJZiB5b3Ugd2FudCB0byBpbnN0ZWFkIGtlZXAgdGhlIHJldHVybiwgcGxlYXNl IHVzZSBwbGFpbiBXQVJOIGluc3RlYWQKPiA+IG9mIFdBUk5fT04uCj4gPgo+ID4gVGhhbmtzLCBS b2dlci4KPiA+Cj4KPiBJcyB0aGVyZSBhbnkgcmVhc29uIHVzaW5nIFdBUk4gdGhhbiBXQVJOX09O PyBCZWNhdXNlIG9mIHRoZSBtZXNzYWdlIHByaW50ZWQgYnkKPiBXQVJOPyBzb21ldGhpbmcgbGlr ZSBiZWxvdz8KCk9oLCBzbyBXQVJOIGFsc28gdGFrZXMgYSBjb25kaXRpb24sIEkgd2FzIGV4cGVj dGluZyBXQVJOIHRvIG5vdCB0YWtlCmFueSBwYXJhbWV0ZXJzLiBKdXN0IHVzZSBXQVJOX09OKHRy dWUpOyB0aGVuLCB0aGVyZSdzIG5vIG5lZWQgdG8KcmUtZXZhbHVhdGUgIW5yX2dyZWZzLgoKX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVsIG1h aWxpbmcgbGlzdApYZW4tZGV2ZWxAbGlzdHMueGVucHJvamVjdC5vcmcKaHR0cHM6Ly9saXN0cy54 ZW5wcm9qZWN0Lm9yZy9tYWlsbWFuL2xpc3RpbmZvL3hlbi1kZXZlbA==