From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: michael.roth@amd.com, isaku.yamahata@intel.com,
Sean Christopherson <seanjc@google.com>
Subject: [PATCH v5 03/17] KVM: x86: use u64_to_user_ptr()
Date: Thu, 4 Apr 2024 08:13:13 -0400 [thread overview]
Message-ID: <20240404121327.3107131-4-pbonzini@redhat.com> (raw)
In-Reply-To: <20240404121327.3107131-1-pbonzini@redhat.com>
There is no danger to the kernel if 32-bit userspace provides a 64-bit
value that has the high bits set, but for whatever reason happens to
resolve to an address that has something mapped there. KVM uses the
checked version of get_user() and put_user(), so any faults are caught
properly.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/x86.c | 24 +++---------------------
1 file changed, 3 insertions(+), 21 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 47d9f03b7778..3d2029402513 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4842,25 +4842,13 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
return r;
}
-static inline void __user *kvm_get_attr_addr(struct kvm_device_attr *attr)
-{
- void __user *uaddr = (void __user*)(unsigned long)attr->addr;
-
- if ((u64)(unsigned long)uaddr != attr->addr)
- return ERR_PTR_USR(-EFAULT);
- return uaddr;
-}
-
static int kvm_x86_dev_get_attr(struct kvm_device_attr *attr)
{
- u64 __user *uaddr = kvm_get_attr_addr(attr);
+ u64 __user *uaddr = u64_to_user_ptr(attr->addr);
if (attr->group)
return -ENXIO;
- if (IS_ERR(uaddr))
- return PTR_ERR(uaddr);
-
switch (attr->attr) {
case KVM_X86_XCOMP_GUEST_SUPP:
if (put_user(kvm_caps.supported_xcr0, uaddr))
@@ -5712,12 +5700,9 @@ static int kvm_arch_tsc_has_attr(struct kvm_vcpu *vcpu,
static int kvm_arch_tsc_get_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr)
{
- u64 __user *uaddr = kvm_get_attr_addr(attr);
+ u64 __user *uaddr = u64_to_user_ptr(attr->addr);
int r;
- if (IS_ERR(uaddr))
- return PTR_ERR(uaddr);
-
switch (attr->attr) {
case KVM_VCPU_TSC_OFFSET:
r = -EFAULT;
@@ -5735,13 +5720,10 @@ static int kvm_arch_tsc_get_attr(struct kvm_vcpu *vcpu,
static int kvm_arch_tsc_set_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr)
{
- u64 __user *uaddr = kvm_get_attr_addr(attr);
+ u64 __user *uaddr = u64_to_user_ptr(attr->addr);
struct kvm *kvm = vcpu->kvm;
int r;
- if (IS_ERR(uaddr))
- return PTR_ERR(uaddr);
-
switch (attr->attr) {
case KVM_VCPU_TSC_OFFSET: {
u64 offset, tsc, ns;
--
2.43.0
next prev parent reply other threads:[~2024-04-04 12:13 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-04 12:13 [PATCH v5 00/17] KVM: SEV: allow customizing VMSA features Paolo Bonzini
2024-04-04 12:13 ` [PATCH v5 01/17] KVM: SVM: Invert handling of SEV and SEV_ES feature flags Paolo Bonzini
2024-04-04 12:13 ` [PATCH v5 02/17] KVM: SVM: Compile sev.c if and only if CONFIG_KVM_AMD_SEV=y Paolo Bonzini
2024-04-04 12:13 ` Paolo Bonzini [this message]
2024-04-04 12:13 ` [PATCH v5 04/17] KVM: introduce new vendor op for KVM_GET_DEVICE_ATTR Paolo Bonzini
2024-04-04 21:30 ` Isaku Yamahata
2024-04-04 12:13 ` [PATCH v5 05/17] KVM: SEV: publish supported VMSA features Paolo Bonzini
2024-04-04 21:32 ` Isaku Yamahata
2024-04-04 12:13 ` [PATCH v5 06/17] KVM: SEV: store VMSA features in kvm_sev_info Paolo Bonzini
2024-04-04 12:13 ` [PATCH v5 07/17] KVM: x86: add fields to struct kvm_arch for CoCo features Paolo Bonzini
2024-04-04 21:39 ` Isaku Yamahata
2024-04-05 23:01 ` Edgecombe, Rick P
2024-04-09 1:21 ` Sean Christopherson
2024-04-09 14:01 ` Edgecombe, Rick P
2024-04-09 14:43 ` Paolo Bonzini
2024-04-09 15:26 ` Sean Christopherson
2024-05-07 23:01 ` Edgecombe, Rick P
2024-05-08 0:21 ` Sean Christopherson
2024-05-08 1:19 ` Edgecombe, Rick P
2024-05-08 14:38 ` Sean Christopherson
2024-05-08 15:04 ` Edgecombe, Rick P
2024-04-04 12:13 ` [PATCH v5 08/17] KVM: x86: Add supported_vm_types to kvm_caps Paolo Bonzini
2024-04-04 12:13 ` [PATCH v5 09/17] KVM: SEV: introduce to_kvm_sev_info Paolo Bonzini
2024-04-04 12:13 ` [PATCH v5 10/17] KVM: SEV: define VM types for SEV and SEV-ES Paolo Bonzini
2024-04-04 12:13 ` [PATCH v5 11/17] KVM: SEV: sync FPU and AVX state at LAUNCH_UPDATE_VMSA time Paolo Bonzini
2024-04-04 12:13 ` [PATCH v5 12/17] KVM: SEV: introduce KVM_SEV_INIT2 operation Paolo Bonzini
2024-04-04 12:13 ` [PATCH v5 13/17] KVM: SEV: allow SEV-ES DebugSwap again Paolo Bonzini
2024-04-04 12:13 ` [PATCH v5 14/17] selftests: kvm: add tests for KVM_SEV_INIT2 Paolo Bonzini
2024-04-04 12:13 ` [PATCH v5 15/17] selftests: kvm: switch to using KVM_X86_*_VM Paolo Bonzini
2024-04-04 12:13 ` [PATCH v5 16/17] selftests: kvm: split "launch" phase of SEV VM creation Paolo Bonzini
2024-04-04 12:13 ` [PATCH v5 17/17] selftests: kvm: add test for transferring FPU state into VMSA Paolo Bonzini
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