summaryrefslogtreecommitdiff
path: root/arch
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2019-04-06 02:43:07 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-04-06 02:43:07 +0300
commitbc5725f97408ce78e61735858a113f514738ba3b (patch)
tree627810fed2a862234996b5b9ad7f03e60456b5bb /arch
parent2f9e10acfa1243a7d0ad323873f4a193144a25c3 (diff)
parentc73f4c998e1fd4249b9edfa39e23f4fda2b9b041 (diff)
downloadlinux-bc5725f97408ce78e61735858a113f514738ba3b.tar.xz
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini: "x86 fixes for overflows and other nastiness" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: nVMX: fix x2APIC VTPR read intercept KVM: x86: nVMX: close leak of L0's x2APIC MSRs (CVE-2019-3887) KVM: SVM: prevent DBG_DECRYPT and DBG_ENCRYPT overflow kvm: svm: fix potential get_num_contig_pages overflow
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/svm.c22
-rw-r--r--arch/x86/kvm/vmx/nested.c74
2 files changed, 59 insertions, 37 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 426039285fd1..e0a791c3d4fc 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -6422,11 +6422,11 @@ e_free:
return ret;
}
-static int get_num_contig_pages(int idx, struct page **inpages,
- unsigned long npages)
+static unsigned long get_num_contig_pages(unsigned long idx,
+ struct page **inpages, unsigned long npages)
{
unsigned long paddr, next_paddr;
- int i = idx + 1, pages = 1;
+ unsigned long i = idx + 1, pages = 1;
/* find the number of contiguous pages starting from idx */
paddr = __sme_page_pa(inpages[idx]);
@@ -6445,12 +6445,12 @@ static int get_num_contig_pages(int idx, struct page **inpages,
static int sev_launch_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp)
{
- unsigned long vaddr, vaddr_end, next_vaddr, npages, size;
+ unsigned long vaddr, vaddr_end, next_vaddr, npages, pages, size, i;
struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
struct kvm_sev_launch_update_data params;
struct sev_data_launch_update_data *data;
struct page **inpages;
- int i, ret, pages;
+ int ret;
if (!sev_guest(kvm))
return -ENOTTY;
@@ -6799,7 +6799,8 @@ static int sev_dbg_crypt(struct kvm *kvm, struct kvm_sev_cmd *argp, bool dec)
struct page **src_p, **dst_p;
struct kvm_sev_dbg debug;
unsigned long n;
- int ret, size;
+ unsigned int size;
+ int ret;
if (!sev_guest(kvm))
return -ENOTTY;
@@ -6807,6 +6808,11 @@ static int sev_dbg_crypt(struct kvm *kvm, struct kvm_sev_cmd *argp, bool dec)
if (copy_from_user(&debug, (void __user *)(uintptr_t)argp->data, sizeof(debug)))
return -EFAULT;
+ if (!debug.len || debug.src_uaddr + debug.len < debug.src_uaddr)
+ return -EINVAL;
+ if (!debug.dst_uaddr)
+ return -EINVAL;
+
vaddr = debug.src_uaddr;
size = debug.len;
vaddr_end = vaddr + size;
@@ -6857,8 +6863,8 @@ static int sev_dbg_crypt(struct kvm *kvm, struct kvm_sev_cmd *argp, bool dec)
dst_vaddr,
len, &argp->error);
- sev_unpin_memory(kvm, src_p, 1);
- sev_unpin_memory(kvm, dst_p, 1);
+ sev_unpin_memory(kvm, src_p, n);
+ sev_unpin_memory(kvm, dst_p, n);
if (ret)
goto err;
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 153e539c29c9..7ec9bb1dd723 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -500,6 +500,17 @@ static void nested_vmx_disable_intercept_for_msr(unsigned long *msr_bitmap_l1,
}
}
+static inline void enable_x2apic_msr_intercepts(unsigned long *msr_bitmap) {
+ int msr;
+
+ for (msr = 0x800; msr <= 0x8ff; msr += BITS_PER_LONG) {
+ unsigned word = msr / BITS_PER_LONG;
+
+ msr_bitmap[word] = ~0;
+ msr_bitmap[word + (0x800 / sizeof(long))] = ~0;
+ }
+}
+
/*
* Merge L0's and L1's MSR bitmap, return false to indicate that
* we do not use the hardware.
@@ -541,39 +552,44 @@ static inline bool nested_vmx_prepare_msr_bitmap(struct kvm_vcpu *vcpu,
return false;
msr_bitmap_l1 = (unsigned long *)kmap(page);
- if (nested_cpu_has_apic_reg_virt(vmcs12)) {
- /*
- * L0 need not intercept reads for MSRs between 0x800 and 0x8ff, it
- * just lets the processor take the value from the virtual-APIC page;
- * take those 256 bits directly from the L1 bitmap.
- */
- for (msr = 0x800; msr <= 0x8ff; msr += BITS_PER_LONG) {
- unsigned word = msr / BITS_PER_LONG;
- msr_bitmap_l0[word] = msr_bitmap_l1[word];
- msr_bitmap_l0[word + (0x800 / sizeof(long))] = ~0;
- }
- } else {
- for (msr = 0x800; msr <= 0x8ff; msr += BITS_PER_LONG) {
- unsigned word = msr / BITS_PER_LONG;
- msr_bitmap_l0[word] = ~0;
- msr_bitmap_l0[word + (0x800 / sizeof(long))] = ~0;
- }
- }
- nested_vmx_disable_intercept_for_msr(
- msr_bitmap_l1, msr_bitmap_l0,
- X2APIC_MSR(APIC_TASKPRI),
- MSR_TYPE_W);
+ /*
+ * To keep the control flow simple, pay eight 8-byte writes (sixteen
+ * 4-byte writes on 32-bit systems) up front to enable intercepts for
+ * the x2APIC MSR range and selectively disable them below.
+ */
+ enable_x2apic_msr_intercepts(msr_bitmap_l0);
+
+ if (nested_cpu_has_virt_x2apic_mode(vmcs12)) {
+ if (nested_cpu_has_apic_reg_virt(vmcs12)) {
+ /*
+ * L0 need not intercept reads for MSRs between 0x800
+ * and 0x8ff, it just lets the processor take the value
+ * from the virtual-APIC page; take those 256 bits
+ * directly from the L1 bitmap.
+ */
+ for (msr = 0x800; msr <= 0x8ff; msr += BITS_PER_LONG) {
+ unsigned word = msr / BITS_PER_LONG;
+
+ msr_bitmap_l0[word] = msr_bitmap_l1[word];
+ }
+ }
- if (nested_cpu_has_vid(vmcs12)) {
- nested_vmx_disable_intercept_for_msr(
- msr_bitmap_l1, msr_bitmap_l0,
- X2APIC_MSR(APIC_EOI),
- MSR_TYPE_W);
nested_vmx_disable_intercept_for_msr(
msr_bitmap_l1, msr_bitmap_l0,
- X2APIC_MSR(APIC_SELF_IPI),
- MSR_TYPE_W);
+ X2APIC_MSR(APIC_TASKPRI),
+ MSR_TYPE_R | MSR_TYPE_W);
+
+ if (nested_cpu_has_vid(vmcs12)) {
+ nested_vmx_disable_intercept_for_msr(
+ msr_bitmap_l1, msr_bitmap_l0,
+ X2APIC_MSR(APIC_EOI),
+ MSR_TYPE_W);
+ nested_vmx_disable_intercept_for_msr(
+ msr_bitmap_l1, msr_bitmap_l0,
+ X2APIC_MSR(APIC_SELF_IPI),
+ MSR_TYPE_W);
+ }
}
if (spec_ctrl)