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| author | Alexander Graf <graf@amazon.com> | 2022-10-17 20:45:40 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-10-22 05:15:56 -0400 |
| commit | 2e3272bc1790825c43d2c39690bf2836b81c6d36 (patch) | |
| tree | c632ac9f2bf8917f5bbd23e5bce547338aae8ea0 | |
| parent | ed51862f2f57cbce6fed2d4278cfe70a490899fd (diff) | |
| download | linux-stable-2e3272bc1790825c43d2c39690bf2836b81c6d36.tar.gz linux-stable-2e3272bc1790825c43d2c39690bf2836b81c6d36.tar.bz2 linux-stable-2e3272bc1790825c43d2c39690bf2836b81c6d36.zip | |
KVM: x86: Copy filter arg outside kvm_vm_ioctl_set_msr_filter()
In the next patch we want to introduce a second caller to
set_msr_filter() which constructs its own filter list on the stack.
Refactor the original function so it takes it as argument instead of
reading it through copy_from_user().
Signed-off-by: Alexander Graf <graf@amazon.com>
Message-Id: <20221017184541.2658-3-graf@amazon.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/x86.c | 31 |
1 files changed, 17 insertions, 14 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 4bd5f8a751de..78f779f0264b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6442,26 +6442,22 @@ static int kvm_add_msr_filter(struct kvm_x86_msr_filter *msr_filter, return 0; } -static int kvm_vm_ioctl_set_msr_filter(struct kvm *kvm, void __user *argp) +static int kvm_vm_ioctl_set_msr_filter(struct kvm *kvm, + struct kvm_msr_filter *filter) { - struct kvm_msr_filter __user *user_msr_filter = argp; struct kvm_x86_msr_filter *new_filter, *old_filter; - struct kvm_msr_filter filter; bool default_allow; bool empty = true; int r = 0; u32 i; - if (copy_from_user(&filter, user_msr_filter, sizeof(filter))) - return -EFAULT; - - if (filter.flags & ~KVM_MSR_FILTER_DEFAULT_DENY) + if (filter->flags & ~KVM_MSR_FILTER_DEFAULT_DENY) return -EINVAL; - for (i = 0; i < ARRAY_SIZE(filter.ranges); i++) - empty &= !filter.ranges[i].nmsrs; + for (i = 0; i < ARRAY_SIZE(filter->ranges); i++) + empty &= !filter->ranges[i].nmsrs; - default_allow = !(filter.flags & KVM_MSR_FILTER_DEFAULT_DENY); + default_allow = !(filter->flags & KVM_MSR_FILTER_DEFAULT_DENY); if (empty && !default_allow) return -EINVAL; @@ -6469,8 +6465,8 @@ static int kvm_vm_ioctl_set_msr_filter(struct kvm *kvm, void __user *argp) if (!new_filter) return -ENOMEM; - for (i = 0; i < ARRAY_SIZE(filter.ranges); i++) { - r = kvm_add_msr_filter(new_filter, &filter.ranges[i]); + for (i = 0; i < ARRAY_SIZE(filter->ranges); i++) { + r = kvm_add_msr_filter(new_filter, &filter->ranges[i]); if (r) { kvm_free_msr_filter(new_filter); return r; @@ -6915,9 +6911,16 @@ set_pit2_out: case KVM_SET_PMU_EVENT_FILTER: r = kvm_vm_ioctl_set_pmu_event_filter(kvm, argp); break; - case KVM_X86_SET_MSR_FILTER: - r = kvm_vm_ioctl_set_msr_filter(kvm, argp); + case KVM_X86_SET_MSR_FILTER: { + struct kvm_msr_filter __user *user_msr_filter = argp; + struct kvm_msr_filter filter; + + if (copy_from_user(&filter, user_msr_filter, sizeof(filter))) + return -EFAULT; + + r = kvm_vm_ioctl_set_msr_filter(kvm, &filter); break; + } default: r = -ENOTTY; } |