KVM: correct error-handling code
Author: Julia Lawall <julia@diku.dk>
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 99017e8..bb4ebd8 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -230,7 +230,7 @@ fail:
if (eventfd && !IS_ERR(eventfd))
eventfd_ctx_put(eventfd);
- if (file && !IS_ERR(file))
+ if (!IS_ERR(file))
fput(file);
kfree(irqfd); |
---
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 99017e8..bb4ebd8 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -230,7 +230,7 @@ fail:
if (eventfd && !IS_ERR(eventfd))
eventfd_ctx_put(eventfd);
- if (file && !IS_ERR(file))
+ if (!IS_ERR(file))
fput(file);
kfree(irqfd);