c/pve-kernel-lowlatency-qoup
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

cherry-pick fixes for CVE-2021-3653 and CVE-2021-3656

Browse Source 
from ubuntu-hirsute upstream/master-next

cherry-pick only the 2 patches, because master-next is 970 commits
ahead of our current master.

Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
This commit is contained in:
Stoiko Ivanov 2021-08-18 16:41:47 +02:00 committed by Wolfgang Bumiller
parent 6714a74b67
commit a7073f6bff
2 changed files with 141 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

96
patches/kernel/0008-UBUNTU-SAUCE-KVM-nSVM-avoid-picking-up-unsupported-b.patch Normal file
View File

@ -0,0 +1,96 @@
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Maxim Levitsky <mlevitsk@redhat.com>
Date: Thu, 29 Jul 2021 17:54:04 +0300
Subject: [PATCH] UBUNTU: SAUCE: KVM: nSVM: avoid picking up unsupported bits
from L2 in int_ctl
This fixes CVE-2021-3653 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.
The bug was discovered by Maxim Levitsky.
Fixes: 3d6368ef580a ("KVM: SVM: Add VMRUN handler")
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
CVE-2021-3653
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Ben Romer <benjamin.romer@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
(cherry picked from commit d4c8d125f361e6aef5d58490672f7efa83dab257)
Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
---
arch/x86/include/asm/svm.h | 2 ++
arch/x86/kvm/svm/nested.c | 11 +++++++----
arch/x86/kvm/svm/svm.c | 8 ++++----
3 files changed, 13 insertions(+), 8 deletions(-)
diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 1c561945b426..6278111bbf97 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -178,6 +178,8 @@ 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/nested.c b/arch/x86/kvm/svm/nested.c
index 0b3bf6e2aeb9..049d3cbbee5a 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -429,7 +429,10 @@ static void nested_prepare_vmcb_save(struct vcpu_svm *svm, struct vmcb *vmcb12)
static void nested_prepare_vmcb_control(struct vcpu_svm *svm)
{
- const u32 mask = V_INTR_MASKING_MASK | V_GIF_ENABLE_MASK | V_GIF_MASK;
+ const u32 int_ctl_vmcb01_bits =
+ V_INTR_MASKING_MASK | V_GIF_MASK | V_GIF_ENABLE_MASK;
+
+ const u32 int_ctl_vmcb12_bits = V_TPR_MASK | V_IRQ_INJECTION_BITS_MASK;
if (nested_npt_enabled(svm))
nested_svm_init_mmu_context(&svm->vcpu);
@@ -437,9 +440,9 @@ static void nested_prepare_vmcb_control(struct vcpu_svm *svm)
svm->vmcb->control.tsc_offset = svm->vcpu.arch.tsc_offset =
svm->vcpu.arch.l1_tsc_offset + svm->nested.ctl.tsc_offset;
- svm->vmcb->control.int_ctl =
- (svm->nested.ctl.int_ctl & ~mask) |
- (svm->nested.hsave->control.int_ctl & mask);
+ svm->vmcb->control.int_ctl =
+ (svm->nested.ctl.int_ctl & int_ctl_vmcb12_bits) |
+ (svm->nested.hsave->control.int_ctl & int_ctl_vmcb01_bits);
svm->vmcb->control.virt_ext = svm->nested.ctl.virt_ext;
svm->vmcb->control.int_vector = svm->nested.ctl.int_vector;
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 786c0eb8bd29..b676386f877e 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1547,17 +1547,17 @@ static void svm_set_vintr(struct vcpu_svm *svm)
static void svm_clear_vintr(struct vcpu_svm *svm)
{
- const u32 mask = V_TPR_MASK | V_GIF_ENABLE_MASK | V_GIF_MASK | V_INTR_MASKING_MASK;
svm_clr_intercept(svm, INTERCEPT_VINTR);
/* Drop int_ctl fields related to VINTR injection. */
- svm->vmcb->control.int_ctl &= mask;
+ svm->vmcb->control.int_ctl &= ~V_IRQ_INJECTION_BITS_MASK;
if (is_guest_mode(&svm->vcpu)) {
- svm->nested.hsave->control.int_ctl &= mask;
+ svm->nested.hsave->control.int_ctl &= ~V_IRQ_INJECTION_BITS_MASK;
WARN_ON((svm->vmcb->control.int_ctl & V_TPR_MASK) !=
(svm->nested.ctl.int_ctl & V_TPR_MASK));
- svm->vmcb->control.int_ctl |= svm->nested.ctl.int_ctl & ~mask;
+ svm->vmcb->control.int_ctl |= svm->nested.ctl.int_ctl &
+ V_IRQ_INJECTION_BITS_MASK;
}
vmcb_mark_dirty(svm->vmcb, VMCB_INTR);

45
patches/kernel/0009-UBUNTU-SAUCE-KVM-nSVM-always-intercept-VMLOAD-VMSAVE.patch Normal file
View File

@ -0,0 +1,45 @@
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Maxim Levitsky <mlevitsk@redhat.com>
Date: Thu, 29 Jul 2021 18:37:38 +0300
Subject: [PATCH] UBUNTU: SAUCE: KVM: nSVM: always intercept VMLOAD/VMSAVE when
nested
If L1 disables VMLOAD/VMSAVE intercepts, and doesn't enable
Virtual VMLOAD/VMSAVE (currently not supported for the nested hypervisor),
then VMLOAD/VMSAVE must operate on the L1 physical memory, which is only
possible by making L0 intercept these instructions.
Failure to do so allowed the nested guest to run VMLOAD/VMSAVE unintercepted,
and thus read/write portions of the host physical memory.
This fixes CVE-2021-3656, which was discovered by Maxim Levitsky and
Paolo Bonzini.
Fixes: 89c8a4984fc9 ("KVM: SVM: Enable Virtual VMLOAD VMSAVE feature")
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
CVE-2021-3656
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Ben Romer <benjamin.romer@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
(cherry picked from commit 7e23c00e809c1669676363962e2ef9df1bd2840b)
Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
---
arch/x86/kvm/svm/nested.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 049d3cbbee5a..3bd5c7d6716e 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -147,6 +147,9 @@ void recalc_intercepts(struct vcpu_svm *svm)
for (i = 0; i < MAX_INTERCEPT; i++)
c->intercepts[i] |= g->intercepts[i];
+
+ vmcb_set_intercept(c, INTERCEPT_VMLOAD);
+ vmcb_set_intercept(c, INTERCEPT_VMSAVE);
}
static void copy_vmcb_control_area(struct vmcb_control_area *dst,