KVM: selftests: AVX support + fixes

[PATCH 01/11] KVM: selftests: Fix out-of-bounds reads in CPUID test's array lookups

Posted by Sean Christopherson 1 month, 3 weeks ago

When looking for a "mangled", i.e. dynamic, CPUID entry, terminate the
walk based on the number of array _entries_, not the size in bytes of
the array.  Iterating based on the total size of the array can result in
false passes, e.g. if the random data beyond the array happens to match
a CPUID entry's function and index.

Fixes: fb18d053b7f8 ("selftest: kvm: x86: test KVM_GET_CPUID2 and guest visible CPUIDs against KVM_GET_SUPPORTED_CPUID")
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 tools/testing/selftests/kvm/x86_64/cpuid_test.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/x86_64/cpuid_test.c b/tools/testing/selftests/kvm/x86_64/cpuid_test.c
index 8c579ce714e9..fec03b11b059 100644
--- a/tools/testing/selftests/kvm/x86_64/cpuid_test.c
+++ b/tools/testing/selftests/kvm/x86_64/cpuid_test.c
@@ -60,7 +60,7 @@ static bool is_cpuid_mangled(const struct kvm_cpuid_entry2 *entrie)
 {
 	int i;
 
-	for (i = 0; i < sizeof(mangled_cpuids); i++) {
+	for (i = 0; i < ARRAY_SIZE(mangled_cpuids); i++) {
 		if (mangled_cpuids[i].function == entrie->function &&
 		    mangled_cpuids[i].index == entrie->index)
 			return true;
-- 
2.47.0.rc0.187.ge670bccf7e-goog

Re: [PATCH 01/11] KVM: selftests: Fix out-of-bounds reads in CPUID test's array lookups

Posted by Vitaly Kuznetsov 1 month, 3 weeks ago

Sean Christopherson <seanjc@google.com> writes:

> When looking for a "mangled", i.e. dynamic, CPUID entry, terminate the
> walk based on the number of array _entries_, not the size in bytes of
> the array.  Iterating based on the total size of the array can result in
> false passes, e.g. if the random data beyond the array happens to match
> a CPUID entry's function and index.
>
> Fixes: fb18d053b7f8 ("selftest: kvm: x86: test KVM_GET_CPUID2 and guest visible CPUIDs against KVM_GET_SUPPORTED_CPUID")
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
>  tools/testing/selftests/kvm/x86_64/cpuid_test.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/kvm/x86_64/cpuid_test.c b/tools/testing/selftests/kvm/x86_64/cpuid_test.c
> index 8c579ce714e9..fec03b11b059 100644
> --- a/tools/testing/selftests/kvm/x86_64/cpuid_test.c
> +++ b/tools/testing/selftests/kvm/x86_64/cpuid_test.c
> @@ -60,7 +60,7 @@ static bool is_cpuid_mangled(const struct kvm_cpuid_entry2 *entrie)
>  {
>  	int i;
>  
> -	for (i = 0; i < sizeof(mangled_cpuids); i++) {
> +	for (i = 0; i < ARRAY_SIZE(mangled_cpuids); i++) {
>  		if (mangled_cpuids[i].function == entrie->function &&
>  		    mangled_cpuids[i].index == entrie->index)
>  			return true;

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>

-- 
Vitaly