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authorAndy Honig <ahonig@google.com>2013-11-19 00:09:22 +0000
committerWilly Tarreau <w@1wt.eu>2014-05-19 07:54:33 +0200
commitba6e9bbbd6e3e28d92ff43981c2354307c095b7c (patch)
tree8ce4da6333d37581928064437c11f3a613737e20
parent4b500c7ff030f35aa6f8badf2f243bc259021e39 (diff)
downloadlinux-linaro-stable-ba6e9bbbd6e3e28d92ff43981c2354307c095b7c.tar.gz
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> Cc: stable@vger.kernel.org Signed-off-by: Andrew Honig <ahonig@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
-rw-r--r--virt/kvm/kvm_main.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 82b6fdca21ba..3b9443be3918 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1846,6 +1846,9 @@ 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);