kernel/kvm-fix-page-struct-leak-in-handle_vmon.patch
2017-01-31 16:22:37 -06:00

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From patchwork Tue Jan 24 10:56:21 2017
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Subject: kvm: fix page struct leak in handle_vmon
From: Paolo Bonzini <pbonzini@redhat.com>
X-Patchwork-Id: 9534885
Message-Id: <1485255381-18069-1-git-send-email-pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: dvyukov@google.com
Date: Tue, 24 Jan 2017 11:56:21 +0100
handle_vmon gets a reference on VMXON region page,
but does not release it. Release the reference.
Found by syzkaller; based on a patch by Dmitry.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
---
arch/x86/kvm/vmx.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 42cc3d6f4d20..0f7345035210 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -7085,13 +7085,18 @@ static int nested_vmx_check_vmptr(struct kvm_vcpu *vcpu, int exit_reason,
}
page = nested_get_page(vcpu, vmptr);
- if (page == NULL ||
- *(u32 *)kmap(page) != VMCS12_REVISION) {
+ if (page == NULL) {
nested_vmx_failInvalid(vcpu);
+ return kvm_skip_emulated_instruction(vcpu);
+ }
+ if (*(u32 *)kmap(page) != VMCS12_REVISION) {
kunmap(page);
+ nested_release_page_clean(page);
+ nested_vmx_failInvalid(vcpu);
return kvm_skip_emulated_instruction(vcpu);
}
kunmap(page);
+ nested_release_page_clean(page);
vmx->nested.vmxon_ptr = vmptr;
break;
case EXIT_REASON_VMCLEAR: