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

[Laine Stump]

On 05/04/2011 07:37 PM, Eric Blake wrote:
> 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,

ACK.