From ccd1fd0c5d4f4cba7fa8642ab466a82db3e9f093 Mon Sep 17 00:00:00 2001 From: Zhao Liu Date: Fri, 23 Feb 2024 16:56:52 +0800 Subject: hw/vfio/iommufd: Fix missing ERRP_GUARD() in iommufd_cdev_getfd() As the comment in qapi/error, dereferencing @errp requires ERRP_GUARD(): * = Why, when and how to use ERRP_GUARD() = * * Without ERRP_GUARD(), use of the @errp parameter is restricted: * - It must not be dereferenced, because it may be null. ... * ERRP_GUARD() lifts these restrictions. * * To use ERRP_GUARD(), add it right at the beginning of the function. * @errp can then be used without worrying about the argument being * NULL or &error_fatal. * * Using it when it's not needed is safe, but please avoid cluttering * the source with useless code. But in iommufd_cdev_getfd(), @errp is dereferenced without ERRP_GUARD(): if (*errp) { error_prepend(errp, VFIO_MSG_PREFIX, path); } Currently, since vfio_attach_device() - the caller of iommufd_cdev_getfd() - is always called in DeviceClass.realize() context and doesn't get the NULL @errp parameter, iommufd_cdev_getfd() hasn't triggered the bug that dereferencing the NULL @errp. To follow the requirement of @errp, add missing ERRP_GUARD() in iommufd_cdev_getfd(). Suggested-by: Markus Armbruster Signed-off-by: Zhao Liu Reviewed-by: Markus Armbruster Message-Id: <20240223085653.1255438-7-zhao1.liu@linux.intel.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/vfio/iommufd.c | 1 + 1 file changed, 1 insertion(+) diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c index 9bfddc1..7baf49e 100644 --- a/hw/vfio/iommufd.c +++ b/hw/vfio/iommufd.c @@ -116,6 +116,7 @@ static void iommufd_cdev_unbind_and_disconnect(VFIODevice *vbasedev) static int iommufd_cdev_getfd(const char *sysfs_path, Error **errp) { + ERRP_GUARD(); long int ret = -ENOTTY; char *path, *vfio_dev_path = NULL, *vfio_path = NULL; DIR *dir = NULL; -- cgit v1.1