[PATCH 1/2] KVM: x86: Fix probable memory leak of vcpu->arch.mce_banks

[PATCH 1/2] KVM: x86: Fix probable memory leak of vcpu->arch.mce_banks

[Wei Yongjun]

vcpu->arch.mce_banks is malloc in kvm_arch_vcpu_init(), but
never free in any place, this may cause memory leak. So this
patch fixed to free it in kvm_arch_vcpu_uninit().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
---
 arch/x86/kvm/x86.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f25b52e..1ddcad4 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5089,6 +5089,7 @@ fail:
 
 void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
 {
+	kfree(vcpu->arch.mce_banks);
 	kvm_free_lapic(vcpu);
 	down_read(&vcpu->kvm->slots_lock);
 	kvm_mmu_destroy(vcpu);
-- 
1.6.2.2

[PATCH 2/2] KVM: x86: Fix leak of free lapic date in kvm_arch_vcpu_init()

[Wei Yongjun]

In function kvm_arch_vcpu_init(), if the memory malloc for
vcpu->arch.mce_banks is fail, it does not free the memory
of lapic date. This patch fixed it.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
---
 arch/x86/kvm/x86.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6651dbf..f25b52e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5072,12 +5072,13 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 				       GFP_KERNEL);
 	if (!vcpu->arch.mce_banks) {
 		r = -ENOMEM;
-		goto fail_mmu_destroy;
+		goto fail_free_lapic;
 	}
 	vcpu->arch.mcg_cap = KVM_MAX_MCE_BANKS;
 
 	return 0;
-
+fail_free_lapic:
+	kvm_free_lapic(vcpu);
 fail_mmu_destroy:
 	kvm_mmu_destroy(vcpu);
 fail_free_pio_data:
-- 
1.6.2.2

[PATCH 1/2 v2] KVM: x86: Fix probable memory leak of vcpu->arch.mce_banks

[Wei Yongjun]

vcpu->arch.mce_banks is malloc in kvm_arch_vcpu_init(), but
never free in any place, this may cause memory leak. So this
patch fixed to free it in kvm_arch_vcpu_uninit().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
---
 arch/x86/kvm/x86.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 56a90a6..c27ebb1 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5470,6 +5470,7 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
 {
 	int idx;
 
+	kfree(vcpu->arch.mce_banks);
 	kvm_free_lapic(vcpu);
 	idx = srcu_read_lock(&vcpu->kvm->srcu);
 	kvm_mmu_destroy(vcpu);

[PATCH] KVM: MMU: Remove some useless code from alloc_mmu_pages()

[Wei Yongjun]

If we fail to alloc page for vcpu->arch.mmu.pae_root, call to
free_mmu_pages() is unnecessary, which just do free the page
malloc for vcpu->arch.mmu.pae_root.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
---
 arch/x86/kvm/mmu.c |    7 ++-----
 1 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 4c3e5b2..5d8e01b 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2849,16 +2849,13 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
 	 */
 	page = alloc_page(GFP_KERNEL | __GFP_DMA32);
 	if (!page)
-		goto error_1;
+		return -ENOMEM;
+
 	vcpu->arch.mmu.pae_root = page_address(page);
 	for (i = 0; i < 4; ++i)
 		vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
 
 	return 0;
-
-error_1:
-	free_mmu_pages(vcpu);
-	return -ENOMEM;
 }
 
 int kvm_mmu_create(struct kvm_vcpu *vcpu)
-- 
1.6.2.2

Re: [PATCH] KVM: MMU: Remove some useless code from alloc_mmu_pages()

[Marcelo Tosatti]

On Fri, Jan 22, 2010 at 04:55:05PM +0800, Wei Yongjun wrote:
> If we fail to alloc page for vcpu->arch.mmu.pae_root, call to
> free_mmu_pages() is unnecessary, which just do free the page
> malloc for vcpu->arch.mmu.pae_root.
> 
> Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>

Applied all 3, thanks.