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| author | Jason Gunthorpe <jgg@nvidia.com> | 2021-04-06 16:40:25 -0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-05-14 09:44:24 +0200 |
| commit | 3d81ce0cfb31293878ccabf6f5e0bf25d3f1f966 (patch) | |
| tree | bf43581f0c4eef48a2db921a9c2f52abaf980b59 /drivers/vfio | |
| parent | e6707395c839f22bcb8aabd795f6f65e2d791d78 (diff) | |
| download | linux-3d81ce0cfb31293878ccabf6f5e0bf25d3f1f966.tar.gz linux-3d81ce0cfb31293878ccabf6f5e0bf25d3f1f966.tar.bz2 linux-3d81ce0cfb31293878ccabf6f5e0bf25d3f1f966.zip | |
vfio/mdev: Do not allow a mdev_type to have a NULL parent pointer
[ Upstream commit b5a1f8921d5040bb788492bf33a66758021e4be5 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/vfio')
| -rw-r--r-- | drivers/vfio/mdev/mdev_sysfs.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c index f32c582611eb..ca9476883f15 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: |