From e3736c3eb3a6f7c0966923b629c9f92b558aa9c7 Mon Sep 17 00:00:00 2001
From: Elena Reshetova <elena.reshetova@intel.com>
Date: Mon, 20 Feb 2017 13:06:21 +0200
Subject: kvm: convert kvm.users_count from atomic_t to refcount_t
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refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
---
 include/linux/kvm_host.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'include')

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 8d69d5150748..2c14ad9809da 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -26,6 +26,7 @@
 #include <linux/context_tracking.h>
 #include <linux/irqbypass.h>
 #include <linux/swait.h>
+#include <linux/refcount.h>
 #include <asm/signal.h>
 
 #include <linux/kvm.h>
@@ -401,7 +402,7 @@ struct kvm {
 #endif
 	struct kvm_vm_stat stat;
 	struct kvm_arch arch;
-	atomic_t users_count;
+	refcount_t users_count;
 #ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
 	struct kvm_coalesced_mmio_ring *coalesced_mmio_ring;
 	spinlock_t ring_lock;
-- 
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