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 3.4-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-3.4 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 @@ -1668,6 +1668,9 @@ 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-3.4/kvm-improve-create-vcpu-parameter-cve-2013-4587.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html