From 0c60fa7f55182b6064b4482022c7b480ce728221 Mon Sep 17 00:00:00 2001 From: Aaron Lewis Date: Thu, 14 Jul 2022 16:13:15 +0000 Subject: [PATCH] KVM: x86: Protect the unused bits in MSR exiting flags [ Upstream commit cf5029d5dd7cb0aaa53250fa9e389abd231606b3 ] The flags for KVM_CAP_X86_USER_SPACE_MSR and KVM_X86_SET_MSR_FILTER have no protection for their unused bits. Without protection, future development for these features will be difficult. Add the protection needed to make it possible to extend these features in the future. Signed-off-by: Aaron Lewis Message-Id: <20220714161314.1715227-1-aaronlewis@google.com> Signed-off-by: Paolo Bonzini Stable-dep-of: 2e3272bc1790 ("KVM: x86: Copy filter arg outside kvm_vm_ioctl_set_msr_filter()") Signed-off-by: Sasha Levin --- arch/x86/kvm/x86.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index cd22557..59c9eb5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5770,6 +5770,11 @@ split_irqchip_unlock: r = 0; break; case KVM_CAP_X86_USER_SPACE_MSR: + r = -EINVAL; + if (cap->args[0] & ~(KVM_MSR_EXIT_REASON_INVAL | + KVM_MSR_EXIT_REASON_UNKNOWN | + KVM_MSR_EXIT_REASON_FILTER)) + break; kvm->arch.user_space_msr_mask = cap->args[0]; r = 0; break; @@ -5903,6 +5908,9 @@ static int kvm_vm_ioctl_set_msr_filter(struct kvm *kvm, void __user *argp) if (copy_from_user(&filter, user_msr_filter, sizeof(filter))) return -EFAULT; + if (filter.flags & ~KVM_MSR_FILTER_DEFAULT_DENY) + return -EINVAL; + for (i = 0; i < ARRAY_SIZE(filter.ranges); i++) empty &= !filter.ranges[i].nmsrs; -- 2.7.4