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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Maxim Levitsky <mlevitsk@redhat.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: [PATCH 4.4 15/31] KVM: nSVM: avoid picking up unsupported bits from L2 in int_ctl (CVE-2021-3653)
Date: Tue, 24 Aug 2021 13:07:27 -0400	[thread overview]
Message-ID: <20210824170743.710957-16-sashal@kernel.org> (raw)
In-Reply-To: <20210824170743.710957-1-sashal@kernel.org>

From: Maxim Levitsky <mlevitsk@redhat.com>

[ upstream commit 0f923e07124df069ba68d8bb12324398f4b6b709 ]

* Invert the mask of bits that we pick from L2 in
  nested_vmcb02_prepare_control

* Invert and explicitly use VIRQ related bits bitmask in svm_clear_vintr

This fixes a security issue that allowed a malicious L1 to run L2 with
AVIC enabled, which allowed the L2 to exploit the uninitialized and enabled
AVIC to read/write the host physical memory at some offsets.

Fixes: 3d6368ef580a ("KVM: SVM: Add VMRUN handler")
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/x86/include/asm/svm.h | 2 ++
 arch/x86/kvm/svm.c         | 6 +++++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 6136d99f537b..c1adb2ed6d41 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -108,6 +108,8 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
 #define V_IGN_TPR_SHIFT 20
 #define V_IGN_TPR_MASK (1 << V_IGN_TPR_SHIFT)
 
+#define V_IRQ_INJECTION_BITS_MASK (V_IRQ_MASK | V_INTR_PRIO_MASK | V_IGN_TPR_MASK)
+
 #define V_INTR_MASKING_SHIFT 24
 #define V_INTR_MASKING_MASK (1 << V_INTR_MASKING_SHIFT)
 
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 931acac69703..77bee73faebc 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2564,7 +2564,11 @@ static bool nested_svm_vmrun(struct vcpu_svm *svm)
 	svm->nested.intercept            = nested_vmcb->control.intercept;
 
 	svm_flush_tlb(&svm->vcpu);
-	svm->vmcb->control.int_ctl = nested_vmcb->control.int_ctl | V_INTR_MASKING_MASK;
+	svm->vmcb->control.int_ctl = nested_vmcb->control.int_ctl &
+			(V_TPR_MASK | V_IRQ_INJECTION_BITS_MASK);
+
+	svm->vmcb->control.int_ctl |= V_INTR_MASKING_MASK;
+
 	if (nested_vmcb->control.int_ctl & V_INTR_MASKING_MASK)
 		svm->vcpu.arch.hflags |= HF_VINTR_MASK;
 	else
-- 
2.30.2


  parent reply	other threads:[~2021-08-24 17:39 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-24 17:07 [PATCH 4.4 00/31] 4.4.282-rc1 review Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 01/31] ASoC: intel: atom: Fix reference to PCM buffer address Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 02/31] i2c: dev: zero out array used for i2c reads from userspace Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 03/31] net: Fix memory leak in ieee802154_raw_deliver Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 04/31] xen/events: Fix race in set_evtchn_to_irq Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 05/31] x86/tools: Fix objdump version check again Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 06/31] PCI/MSI: Enable and mask MSI-X early Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 07/31] PCI/MSI: Do not set invalid bits in MSI mask Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 08/31] PCI/MSI: Correct misleading comments Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 09/31] PCI/MSI: Use msi_mask_irq() in pci_msi_shutdown() Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 10/31] PCI/MSI: Protect msi_desc::masked for multi-MSI Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 11/31] PCI/MSI: Mask all unused MSI-X entries Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 12/31] PCI/MSI: Enforce that MSI-X table entry is masked for update Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 13/31] PCI/MSI: Enforce MSI[X] entry updates to be visible Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 14/31] vmlinux.lds.h: Handle clang's module.{c,d}tor sections Sasha Levin
2021-08-24 17:07 ` Sasha Levin [this message]
2021-08-24 17:07 ` [PATCH 4.4 16/31] dmaengine: usb-dmac: Fix PM reference leak in usb_dmac_probe() Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 17/31] ARM: dts: am43x-epos-evm: Reduce i2c0 bus speed for tps65218 Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 18/31] dmaengine: of-dma: router_xlate to return -EPROBE_DEFER if controller is not yet available Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 19/31] scsi: megaraid_mm: Fix end of loop tests for list_for_each_entry() Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 20/31] scsi: core: Avoid printing an error if target_alloc() returns -ENXIO Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 21/31] Bluetooth: hidp: use correct wait queue when removing ctrl_wait Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 22/31] dccp: add do-while-0 stubs for dccp_pr_debug macros Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 23/31] net: 6pack: fix slab-out-of-bounds in decode_data Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 24/31] net: qlcnic: add missed unlock in qlcnic_83xx_flash_read32 Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 25/31] mmc: dw_mmc: Wait for data transfer after response errors Sasha Levin
2021-08-26 11:59   ` Nobuhiro Iwamatsu
2021-08-26 12:31     ` Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 26/31] mmc: dw_mmc: call the dw_mci_prep_stop_abort() by default Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 27/31] mmc: dw_mmc: Fix hang on data CRC error Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 28/31] ALSA: hda - fix the 'Capture Switch' value change notifications Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 29/31] ipack: tpci200: fix many double free issues in tpci200_pci_probe Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 30/31] ASoC: intel: atom: Fix breakage for PCM buffer address setup Sasha Levin
2021-08-24 17:07 ` [PATCH 4.4 31/31] Linux 4.4.282-rc1 Sasha Levin
2021-08-25  7:33 ` [PATCH 4.4 00/31] 4.4.282-rc1 review Pavel Machek
2021-08-25 20:27 ` Guenter Roeck
2021-08-25 21:18 ` Daniel Díaz
2021-08-25 22:38 ` Shuah Khan

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