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Patch "kvm: fix page struct leak in handle_vmon" has been added to the 3.18-stable tree

PATCH [email protected] 1 participant 1 message Apr 18, 2017

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This is a note to let you know that I've just added the patch titled

kvm: fix page struct leak in handle_vmon

to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
kvm-fix-page-struct-leak-in-handle_vmon.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 06ce521af9558814b8606c0476c54497cf83a653 Mon Sep 17 00:00:00 2001

From: Paolo Bonzini <[email protected]>
Date: Tue, 24 Jan 2017 11:56:21 +0100
Subject: kvm: fix page struct leak in handle_vmon

From: Paolo Bonzini <[email protected]>

commit 06ce521af9558814b8606c0476c54497cf83a653 upstream.

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.

[bwh: Backported to 3.16: use skip_emulated_instruction()]
---
 arch/x86/kvm/vmx.c |   10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
arch/x86/kvm/vmx.c +8 -2
@@ -6079,14 +6079,20 @@ 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);
+			skip_emulated_instruction(vcpu);
+			return 1;
+		}
+		if (*(u32 *)kmap(page) != VMCS12_REVISION) {
 			kunmap(page);
+			nested_release_page_clean(page);
+			nested_vmx_failInvalid(vcpu);
 			skip_emulated_instruction(vcpu);
 			return 1;
 		}
 		kunmap(page);
+		nested_release_page_clean(page);
 		vmx->nested.vmxon_ptr = vmptr;
 		break;
 	case EXIT_REASON_VMCLEAR:

Patches currently in stable-queue which might be from [email protected] are

queue-3.18/kvm-fix-page-struct-leak-in-handle_vmon.patch