[PATCH 4.19 04/81] KVM: SVM: Fix potential memory leak in svm_cpu_init()

From: Greg Kroah-Hartman
Date: Tue May 26 2020 - 15:03:03 EST


From: Miaohe Lin <linmiaohe@xxxxxxxxxx>

commit d80b64ff297e40c2b6f7d7abc1b3eba70d22a068 upstream.

When kmalloc memory for sd->sev_vmcbs failed, we forget to free the page
held by sd->save_area. Also get rid of the var r as '-ENOMEM' is actually
the only possible outcome here.

Reviewed-by: Liran Alon <liran.alon@xxxxxxxxxx>
Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/x86/kvm/svm.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -998,33 +998,32 @@ static void svm_cpu_uninit(int cpu)
static int svm_cpu_init(int cpu)
{
struct svm_cpu_data *sd;
- int r;

sd = kzalloc(sizeof(struct svm_cpu_data), GFP_KERNEL);
if (!sd)
return -ENOMEM;
sd->cpu = cpu;
- r = -ENOMEM;
sd->save_area = alloc_page(GFP_KERNEL);
if (!sd->save_area)
- goto err_1;
+ goto free_cpu_data;

if (svm_sev_enabled()) {
- r = -ENOMEM;
sd->sev_vmcbs = kmalloc_array(max_sev_asid + 1,
sizeof(void *),
GFP_KERNEL);
if (!sd->sev_vmcbs)
- goto err_1;
+ goto free_save_area;
}

per_cpu(svm_data, cpu) = sd;

return 0;

-err_1:
+free_save_area:
+ __free_page(sd->save_area);
+free_cpu_data:
kfree(sd);
- return r;
+ return -ENOMEM;

}