[RFC 2/2] kvm: eventfd: detect integer overflow using check_*_overflow

[Sasha Levin]

Detect integer overflows using safe operations rather than relying on
undefined behaviour.

Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
---
 virt/kvm/eventfd.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index 148b239..2eb044f 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -790,7 +790,7 @@ kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
 	}
 
 	/* check for range overflow */
-	if (args->addr + args->len < args->addr)
+	if (check_add_overflow(args->len, args->addr))
 		return -EINVAL;
 
 	/* check for extra flags that we don't understand */
-- 
1.7.10.4

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