From: Jan Kiszka <[email protected]> So far, KVM copied the emulated_msrs (only MSR_IA32_MISC_ENABLE) to a wrong address in user space due to broken pointer arithmetic. This caused subtle corruption up there (missing MSR_IA32_MISC_ENABLE had probably no practical relevance). Moreover, the size check for the user-provided kvm_msr_list forgot about emulated MSRs.
Signed-off-by: Jan Kiszka <[email protected]> Signed-off-by: Avi Kivity <[email protected]> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 54dcfa4..6dde99c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1256,14 +1256,13 @@ long kvm_arch_dev_ioctl(struct file *filp, if (copy_to_user(user_msr_list, &msr_list, sizeof msr_list)) goto out; r = -E2BIG; - if (n < num_msrs_to_save) + if (n < msr_list.nmsrs) goto out; r = -EFAULT; if (copy_to_user(user_msr_list->indices, &msrs_to_save, num_msrs_to_save * sizeof(u32))) goto out; - if (copy_to_user(user_msr_list->indices - + num_msrs_to_save * sizeof(u32), + if (copy_to_user(user_msr_list->indices + num_msrs_to_save, &emulated_msrs, ARRAY_SIZE(emulated_msrs) * sizeof(u32))) goto out; -- To unsubscribe from this list: send the line "unsubscribe kvm-commits" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
