From f187a1b90b32aae3b3ab26cdda2b8c9e2a91f352 Mon Sep 17 00:00:00 2001 From: Parav Pandit Date: Fri, 24 May 2019 10:59:42 +0800 Subject: [PATCH] vfio/mdev: Fix aborting mdev child device removal if one fails mainline inclusion from mainline-5.2-rc1 commit 6093e348a5e2 category: bugfix bugzilla: 15887 CVE: NA ------------------------------------------------- device_for_each_child() stops executing callback function for remaining child devices, if callback hits an error. Each child mdev device is independent of each other. While unregistering parent device, mdev core must remove all child mdev devices. Therefore, mdev_device_remove_cb() always returns success so that device_for_each_child doesn't abort if one child removal hits error. While at it, improve remove and unregister functions for below simplicity. There isn't need to pass forced flag pointer during mdev parent removal which invokes mdev_device_remove(). So simplify the flow. mdev_device_remove() is called from two paths. 1. mdev_unregister_driver() mdev_device_remove_cb() mdev_device_remove() 2. remove_store() mdev_device_remove() Fixes: 7b96953bc640 ("vfio: Mediated device Core driver") Reviewed-by: Maxim Levitsky Signed-off-by: Parav Pandit Signed-off-by: Alex Williamson Signed-off-by: Yang Yingliang Reviewed-by: Xuefeng Wang Signed-off-by: Yang Yingliang --- drivers/vfio/mdev/mdev_core.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c index 0212f0ee8aea..1506647573c0 100644 --- a/drivers/vfio/mdev/mdev_core.c +++ b/drivers/vfio/mdev/mdev_core.c @@ -150,10 +150,10 @@ static int mdev_device_remove_ops(struct mdev_device *mdev, bool force_remove) static int mdev_device_remove_cb(struct device *dev, void *data) { - if (!dev_is_mdev(dev)) - return 0; + if (dev_is_mdev(dev)) + mdev_device_remove(dev, true); - return mdev_device_remove(dev, data ? *(bool *)data : true); + return 0; } /* @@ -240,7 +240,6 @@ EXPORT_SYMBOL(mdev_register_device); void mdev_unregister_device(struct device *dev) { struct mdev_parent *parent; - bool force_remove = true; mutex_lock(&parent_list_lock); parent = __find_parent_device(dev); @@ -254,8 +253,7 @@ void mdev_unregister_device(struct device *dev) list_del(&parent->next); class_compat_remove_link(mdev_bus_compat_class, dev, NULL); - device_for_each_child(dev, (void *)&force_remove, - mdev_device_remove_cb); + device_for_each_child(dev, NULL, mdev_device_remove_cb); parent_remove_sysfs_files(parent); -- GitLab