From 6223011fb9f90fab92635f1f782196cbd2ccf24f Mon Sep 17 00:00:00 2001 From: Julia Lawall Date: Tue, 28 Jul 2009 17:53:24 +0200 Subject: [PATCH] KVM: correct error-handling code This code is not executed before file has been initialized to the result of calling eventfd_fget. This function returns an ERR_PTR value in an error case instead of NULL. Thus the test that file is not NULL is always true. A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // @match exists@ expression x, E; statement S1, S2; @@ x = eventfd_fget(...) ... when != x = E ( * if (x == NULL || ...) S1 else S2 | * if (x == NULL && ...) S1 else S2 ) // Signed-off-by: Julia Lawall Signed-off-by: Avi Kivity --- 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 99017e8a92ac..bb4ebd89b9ff 100644 --- a/virt/kvm/eventfd.c +++ b/virt/kvm/eventfd.c @@ -230,7 +230,7 @@ kvm_irqfd_assign(struct kvm *kvm, int fd, int gsi) if (eventfd && !IS_ERR(eventfd)) eventfd_ctx_put(eventfd); - if (file && !IS_ERR(file)) + if (!IS_ERR(file)) fput(file); kfree(irqfd);