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KVM: x86: Fix probable memory leak of vcpu->arch.mce_banks

PATCH Superseded Wei Yongjun 2 participants 5 messages Jan 22, 2010 – Jan 23, 2010

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x86 KVM KVM x86
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Wei Yongjun

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#0 lore raw

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

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 <[email protected]>
---
 arch/x86/kvm/x86.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
arch/x86/kvm/x86.c +1 -0
index f25b52e..1ddcad4 100644
@@ -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);
Signature · 1 line
1.6.2.2
author
#1 lore raw

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

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 <[email protected]>
---
 arch/x86/kvm/x86.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)
arch/x86/kvm/x86.c +3 -2
index 6651dbf..f25b52e 100644
@@ -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:
Signature · 1 line
1.6.2.2
author
#2 lore raw

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

In reply to 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 <[email protected]>
---
 arch/x86/kvm/x86.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
arch/x86/kvm/x86.c +1 -0
index 56a90a6..c27ebb1 100644
@@ -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);
author
#3 lore raw

PATCH 1/1 KVM: MMU: Remove some useless code from alloc_mmu_pages()

In reply to 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 <[email protected]>
---
 arch/x86/kvm/mmu.c |    7 ++-----
 1 files changed, 2 insertions(+), 5 deletions(-)
arch/x86/kvm/mmu.c +2 -5
index 4c3e5b2..5d8e01b 100644
@@ -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)
Signature · 1 line
1.6.2.2
Applied
#4 lore raw

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

Quoted 5 lines · 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 <[email protected]>

Applied all 3, thanks.