lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 28 Jul 2010 14:18:22 +0200 From: "Roedel, Joerg" <Joerg.Roedel@....com> To: Avi Kivity <avi@...hat.com> CC: Marcelo Tosatti <mtosatti@...hat.com>, "kvm@...r.kernel.org" <kvm@...r.kernel.org>, "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org> Subject: Re: [PATCH 2/2] KVM: SVM: Emulate next_rip svm feature On Wed, Jul 28, 2010 at 07:57:36AM -0400, Avi Kivity wrote: > If the instruction opcode is on mmio, the processor never sees the > opcode and thus can not intercept. Or the processor may see one > instruction, which is not intercepted, but by the time the emulator > kicks in a different instruction takes its place, since another vcpu is > evilly cross-modifying the code. Right. X-modifying code is a problem too. > The guest (L2 in this case) is doomed since it execution cannot > continue. But L1 and L0 are fine. The problem with L2 avoiding > intercepts is that L2 can change control registers and take over L1. Right too. We can not ignore it. The right fix is probably a check for the instruction intercepts right after the decoder has run and before the emulator ran. Joer -- Joerg Roedel - AMD Operating System Research Center Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach General Managers: Alberto Bozzo, Andrew Bowd Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists