This is a note to let you know that I've just added the patch titled
KVM: Improve create VCPU parameter (CVE-2013-4587)
to the 3.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-improve-create-vcpu-parameter-cve-2013-4587.patch
and it can be found in the queue-3.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 338c7dbadd2671189cec7faf64c84d01071b3f96 Mon Sep 17 00:00:00 2001
From: Andy Honig <ahonig@xxxxxxxxxx>
Date: Mon, 18 Nov 2013 16:09:22 -0800
Subject: KVM: Improve create VCPU parameter (CVE-2013-4587)
From: Andy Honig <ahonig@xxxxxxxxxx>
commit 338c7dbadd2671189cec7faf64c84d01071b3f96 upstream.
In multiple functions the vcpu_id is used as an offset into a bitfield. Ag
malicious user could specify a vcpu_id greater than 255 in order to set or
clear bits in kernel memory. This could be used to elevate priveges in the
kernel. This patch verifies that the vcpu_id provided is less than 255.
The api documentation already specifies that the vcpu_id must be less than
max_vcpus, but this is currently not checked.
Reported-by: Andrew Honig <ahonig@xxxxxxxxxx>
Signed-off-by: Andrew Honig <ahonig@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
virt/kvm/kvm_main.c | 3 +++
1 file changed, 3 insertions(+)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1893,6 +1893,9 @@ static int kvm_vm_ioctl_create_vcpu(stru
int r;
struct kvm_vcpu *vcpu, *v;
+ if (id >= KVM_MAX_VCPUS)
+ return -EINVAL;
+
vcpu = kvm_arch_vcpu_create(kvm, id);
if (IS_ERR(vcpu))
return PTR_ERR(vcpu);
Patches currently in stable-queue which might be from ahonig@xxxxxxxxxx are
queue-3.12/kvm-x86-convert-vapic-synchronization-to-_cached-functions-cve-2013-6368.patch
queue-3.12/kvm-improve-create-vcpu-parameter-cve-2013-4587.patch
queue-3.12/kvm-x86-fix-potential-divide-by-0-in-lapic-cve-2013-6367.patch
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