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 C4EDEC7EE2C for ; Fri, 26 May 2023 23:51:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230433AbjEZXu4 (ORCPT ); Fri, 26 May 2023 19:50:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35346 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231341AbjEZXuw (ORCPT ); Fri, 26 May 2023 19:50:52 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AAAC183 for ; Fri, 26 May 2023 16:50:51 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-565a66a5d84so17911637b3.0 for ; Fri, 26 May 2023 16:50:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1685145051; x=1687737051; h=cc:to:from:subject:message-id:mime-version:date:reply-to:from:to:cc :subject:date:message-id:reply-to; bh=GrrbCTNmuoStmkrRuA8nAkDHAJuHJg+G1Ouxa5BEv0E=; b=mTELTflySAQiCs9/L8ypvXX/eTvO6pIM2XukZz0HRry6ElpVfxuvF3c5N068qIlCAk k9AwIdmbQMpqPeMRBvZZrTdMrkC9Z7Vu0RCDajLwkIiIUp3HgRvBSggzqGb/HZAY7ovb bLRpUxscmxUk737WD9naghz/xT0aukmgjM9ooxoCqHhDcv5S+M+1VlxM9blNYxTHThdx oWi5spgRGEmKEet0XuSz26RRSwWMS/ame/liPHy7UP6yNZYoSBp1Sd3yznXvwglCFW1z 35S9pH9rfzByljMOnIy9ZkQsaM7E6zOGuJg9DGSp7ZWeuUXnUpd11aQMyeUjsYaLwU8v yOwQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685145051; x=1687737051; h=cc:to:from:subject:message-id:mime-version:date:reply-to :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=GrrbCTNmuoStmkrRuA8nAkDHAJuHJg+G1Ouxa5BEv0E=; b=H20K4iJJgCkXaDCLQqnQESXv+qRiAGOi+cvaVUbPNo+QwlWqs9gaAFQV2C4fFEfRV5 cbAy4KPL7Q4LRos4Rt+MmRTa2ZlMJwXjAvoSL+fz63HXahKT7iAFhEZS0lEzfGfwVMGQ dmho431c5HwQDbEqvkP4u9I7zNrhk1PyUNhRcRUb/j5AmKop+4RFZC+wIbz9uJks6IA2 2puK4njp+Dy8Cd/eA2psMJNAmoaCa6fwf5GYlmcTu4MrQW1VCmf5tQ+s0wheX2IZCfsK SamtAZxnNSJXLyUfQQilNAmVuz/mJxM8IgfnaTtHnaRpIAFGzAymaAQ4VvDbDnJk0lWE V9FQ== X-Gm-Message-State: AC+VfDwLka6OA8sY1tbM8pdOxzB8T4QN6FAKFN7i9i6kK0xTbau2PrHt ks0soJKKR46slEMxvF+1giiR2tHQlg8= X-Google-Smtp-Source: ACHHUZ7jwct2wpyWq7yunLwSh70YAsCdVUzujKPG4lOkNzlIVbE7aRs+7mCaFuepIiYMflTyG3QxO3elvYk= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a81:4050:0:b0:561:8ff6:fb5b with SMTP id m16-20020a814050000000b005618ff6fb5bmr1955724ywn.10.1685145051003; Fri, 26 May 2023 16:50:51 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 26 May 2023 16:50:45 -0700 Mime-Version: 1.0 X-Mailer: git-send-email 2.41.0.rc0.172.g3f132b7071-goog Message-ID: <20230526235048.2842761-1-seanjc@google.com> Subject: [PATCH v2 0/3] KVM: x86: Out-of-bounds access in kvm_recalculate_phys_map() From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Michal Luczaj Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org v2 of Michal's fix for a TOCTOU bug in kvm_recalculate_phys_map(). Not fully tested (will do that next week), though I did confirm the reworked selftest can hit the bug. Posting a bit prematurely as I have a long weekend and I don't want Michal to do any duplicate work. In Michal's words... kvm_recalculate_apic_map() creates the APIC map iterating over the list of vCPUs twice. First to find the max APIC ID and allocate a max-sized buffer, then again, calling kvm_recalculate_phys_map() for each vCPU. This opens a race window: value of max APIC ID can increase _after_ the buffer was allocated. Michal Luczaj (1): KVM: selftests: Add test for race in kvm_recalculate_apic_map() Sean Christopherson (2): KVM: x86: Bail from kvm_recalculate_phys_map() if x2APIC ID is out-of-bounds KVM: x86: Retry APIC optimized map recalc if vCPU is added/enabled arch/x86/kvm/lapic.c | 49 ++++++++++-- tools/testing/selftests/kvm/Makefile | 1 + .../kvm/x86_64/recalc_apic_map_race.c | 76 +++++++++++++++++++ 3 files changed, 120 insertions(+), 6 deletions(-) create mode 100644 tools/testing/selftests/kvm/x86_64/recalc_apic_map_race.c base-commit: 39428f6ea9eace95011681628717062ff7f5eb5f -- 2.41.0.rc0.172.g3f132b7071-goog