linux/debian/patches/bugfix/x86/kvm-fix-page-struct-leak-in...

41 lines
1.3 KiB
Diff

From: Paolo Bonzini <pbonzini@redhat.com>
Date: Tue, 24 Jan 2017 11:56:21 +0100
Subject: kvm: fix page struct leak in handle_vmon
Origin: https://git.kernel.org/linus/06ce521af9558814b8606c0476c54497cf83a653
Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2017-2596
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>
---
arch/x86/kvm/vmx.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -7085,13 +7085,18 @@ static int nested_vmx_check_vmptr(struct
}
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: