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| author | Andy Honig <ahonig@google.com> | 2013-11-18 16:09:22 -0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2013-12-12 22:39:33 +0100 |
| commit | 338c7dbadd2671189cec7faf64c84d01071b3f96 (patch) | |
| tree | f8aa565a09db010f6a5693051197bcb75073108a /virt/kvm/kvm_main.c | |
| parent | 2e7babfa892a55588467ef03b545002e32f31528 (diff) | |
| download | lwn-338c7dbadd2671189cec7faf64c84d01071b3f96.tar.gz lwn-338c7dbadd2671189cec7faf64c84d01071b3f96.zip | |
KVM: Improve create VCPU parameter (CVE-2013-4587)
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>
Cc: stable@vger.kernel.org
Signed-off-by: Andrew Honig <ahonig@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt/kvm/kvm_main.c')
| -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 a0aa84b5941a..4f588bc94186 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1898,6 +1898,9 @@ 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); |