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| author | Andy Honig <ahonig@google.com> | 2013-11-18 16:09:22 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-12-20 07:45:07 -0800 |
| commit | f4d838225e0cbdc8099c2eb8d55dd9406def1f33 (patch) | |
| tree | ce82eab11ef8913393eeb58b66e528d2480e78cb | |
| parent | a5633d4871bae973f39945b2ba0f86f6bbd45ab4 (diff) | |
| download | linux-stable-f4d838225e0cbdc8099c2eb8d55dd9406def1f33.tar.gz linux-stable-f4d838225e0cbdc8099c2eb8d55dd9406def1f33.tar.bz2 linux-stable-f4d838225e0cbdc8099c2eb8d55dd9406def1f33.zip | |
KVM: Improve create VCPU parameter (CVE-2013-4587)
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@google.com>
Signed-off-by: Andrew Honig <ahonig@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | virt/kvm/kvm_main.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 302681c4aa44..eb99458f5b68 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1904,6 +1904,9 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id) 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); |