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authorJason Gunthorpe <jgg@nvidia.com>2021-04-06 21:40:25 +0200
committerAlex Williamson <alex.williamson@redhat.com>2021-04-07 23:39:16 +0200
commitb5a1f8921d5040bb788492bf33a66758021e4be5 (patch)
tree409c68be592aa60d6e9f90328dbc0117ca442805 /drivers/vfio/mdev
parentvfio/mdev: Fix missing static's on MDEV_TYPE_ATTR's (diff)
downloadlinux-b5a1f8921d5040bb788492bf33a66758021e4be5.tar.xz
linux-b5a1f8921d5040bb788492bf33a66758021e4be5.zip
vfio/mdev: Do not allow a mdev_type to have a NULL parent pointer
There is a small race where the parent is NULL even though the kobj has already been made visible in sysfs. For instance the attribute_group is made visible in sysfs_create_files() and the mdev_type_attr_show() does: ret = attr->show(kobj, type->parent->dev, buf); Which will crash on NULL parent. Move the parent setup to before the type pointer leaves the stack frame. Fixes: 7b96953bc640 ("vfio: Mediated device Core driver") Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Message-Id: <2-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio/mdev')
-rw-r--r--drivers/vfio/mdev/mdev_sysfs.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c
index 917fd84c1c6f..367ff5412a38 100644
--- a/drivers/vfio/mdev/mdev_sysfs.c
+++ b/drivers/vfio/mdev/mdev_sysfs.c
@@ -105,6 +105,7 @@ static struct mdev_type *add_mdev_supported_type(struct mdev_parent *parent,
return ERR_PTR(-ENOMEM);
type->kobj.kset = parent->mdev_types_kset;
+ type->parent = parent;
ret = kobject_init_and_add(&type->kobj, &mdev_type_ktype, NULL,
"%s-%s", dev_driver_string(parent->dev),
@@ -132,7 +133,6 @@ static struct mdev_type *add_mdev_supported_type(struct mdev_parent *parent,
}
type->group = group;
- type->parent = parent;
return type;
attrs_failed: