[PATCH] kvm: Ensure negative return value on kvm_init() error handling path

From: Eduardo Habkost <ehabkost@redhat.com>
To: qemu-devel@nongnu.org, Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Subject: [PATCH] kvm: Ensure negative return value on kvm_init() error handling path
Date: Fri, 30 May 2014 17:26:22 -0300	[thread overview]
Message-ID: <1401481582-26007-1-git-send-email-ehabkost@redhat.com> (raw)

We need to ensure ret < 0 when going through the error path, or QEMU may
try to run the half-initialized VM and crash.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 kvm-all.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kvm-all.c b/kvm-all.c
index 721a390..4e19eff 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1410,7 +1410,7 @@ int kvm_init(MachineClass *mc)
 
     ret = kvm_ioctl(s, KVM_GET_API_VERSION, 0);
     if (ret < KVM_API_VERSION) {
-        if (ret > 0) {
+        if (ret >= 0) {
             ret = -EINVAL;
         }
         fprintf(stderr, "kvm version too old\n");
@@ -1461,6 +1461,7 @@ int kvm_init(MachineClass *mc)
     if (mc->kvm_type) {
         type = mc->kvm_type(kvm_type);
     } else if (kvm_type) {
+        ret = -EINVAL;
         fprintf(stderr, "Invalid argument kvm-type=%s\n", kvm_type);
         goto err;
     }
@@ -1561,6 +1562,7 @@ int kvm_init(MachineClass *mc)
     return 0;
 
 err:
+    assert(ret < 0);
     if (s->vmfd >= 0) {
         close(s->vmfd);
     }
-- 
1.9.0

