[libvirt] [PATCH 2/2] node_device: avoid null dereference on error

[Eric Blake]

If we plow on after udev_device_get_syspath fails, we will hit a NULL
dereference.  Clang found one due to strdup later in udevSetParent,
but in fact we hit a NULL dereference sooner because of the use of
STREQ within virNodeDeviceFindBySysfsPath.

* src/conf/node_device_conf.h (virNodeDeviceFindBySysfsPath): Mark
path argument non-null.
* src/node_device/node_device_udev.c (udevSetParent): Avoid null
dereference.
---
 src/conf/node_device_conf.h        |    5 +++--
 src/node_device/node_device_udev.c |    6 ++++--
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/conf/node_device_conf.h b/src/conf/node_device_conf.h
index 975abb3..e90bdc5 100644
--- a/src/conf/node_device_conf.h
+++ b/src/conf/node_device_conf.h
@@ -1,7 +1,7 @@
 /*
  * node_device_conf.h: config handling for node devices
  *
- * Copyright (C) 2010 Red Hat, Inc.
+ * Copyright (C) 2010-2011 Red Hat, Inc.
  * Copyright (C) 2008 Virtual Iron Software, Inc.
  * Copyright (C) 2008 David F. Lively
  *
@@ -228,7 +228,8 @@ virNodeDeviceObjPtr virNodeDeviceFindByName(const virNodeDeviceObjListPtr devs,
                                             const char *name);
 virNodeDeviceObjPtr
 virNodeDeviceFindBySysfsPath(const virNodeDeviceObjListPtr devs,
-                             const char *sysfs_path);
+                             const char *sysfs_path)
+    ATTRIBUTE_NONNULL(2);

 virNodeDeviceObjPtr virNodeDeviceAssignDef(virNodeDeviceObjListPtr devs,
                                            const virNodeDeviceDefPtr def);
diff --git a/src/node_device/node_device_udev.c b/src/node_device/node_device_udev.c
index 8cf0e82..9cca375 100644
--- a/src/node_device/node_device_udev.c
+++ b/src/node_device/node_device_udev.c
@@ -1236,8 +1236,10 @@ static int udevSetParent(struct udev_device *device,

         parent_sysfs_path = udev_device_get_syspath(parent_device);
         if (parent_sysfs_path == NULL) {
-            VIR_DEBUG("Could not get syspath for parent of '%s'",
-                      udev_device_get_syspath(parent_device));
+            virNodeDeviceReportError(VIR_ERR_INTERNAL_ERROR,
+                                     _("Could not get syspath for parent of '%s'"),
+                                     udev_device_get_syspath(parent_device));
+            goto out;
         }

         dev = virNodeDeviceFindBySysfsPath(&driverState->devs,
-- 
1.7.4.4