We only allocate memory for 32 MCE banks (KVM_MAX_MCE_BANKS) but we allow user space to fill up to 255 on setup (mcg_cap & 0xff), corrupting kernel memory. Catch these overflows. Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> --- arch/x86/kvm/x86.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c1e9094..e2fb5e0 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1720,7 +1720,7 @@ static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu, unsigned bank_num = mcg_cap & 0xff, bank; r = -EINVAL; - if (!bank_num) + if (!bank_num || bank_num >= KVM_MAX_MCE_BANKS) goto out; if (mcg_cap & ~(KVM_MCE_CAP_SUPPORTED | 0xff | 0xff0000)) goto out; -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
