diff options
| author | Andy Honig <ahonig@google.com> | 2013-11-18 16:09:22 -0800 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2014-01-03 04:33:31 +0000 |
| commit | 4a94970b318e0d7387c2d84fa7c92ea782ae52b3 (patch) | |
| tree | 3bd46437e963944ea3bf3c4609dcb8eebc402681 /virt | |
| parent | 96e7025c23fe7d09401edbfa8990144cbf8dc93b (diff) | |
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: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'virt')
| -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 8bf05f055c0a..bfa8e1e75a48 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1683,6 +1683,9 @@ 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); |