From: Tobin C. Harding tobin@kernel.org
commit e32773357d5cc271b1d23550b3ed026eb5c2a468 upstream.
A failed call to kobject_init_and_add() must be followed by a call to kobject_put(). Currently in the error path when adding fs_devices we are missing this call. This could be fixed by calling btrfs_sysfs_remove_fsid() if btrfs_sysfs_add_fsid() returns an error or by adding a call to kobject_put() directly in btrfs_sysfs_add_fsid(). Here we choose the second option because it prevents the slightly unusual error path handling requirements of kobject from leaking out into btrfs functions.
Add a call to kobject_put() in the error path of kobject_add_and_init(). This causes the release method to be called if kobject_init_and_add() fails. open_tree() is the function that calls btrfs_sysfs_add_fsid() and the error code in this function is already written with the assumption that the release method is called during the error path of open_tree() (as seen by the call to btrfs_sysfs_remove_fsid() under the fail_fsdev_sysfs label).
Cc: stable@vger.kernel.org # v4.4+ Reviewed-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Tobin C. Harding tobin@kernel.org Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/btrfs/sysfs.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -794,7 +794,12 @@ int btrfs_sysfs_add_fsid(struct btrfs_fs fs_devs->fsid_kobj.kset = btrfs_kset; error = kobject_init_and_add(&fs_devs->fsid_kobj, &btrfs_ktype, parent, "%pU", fs_devs->fsid); - return error; + if (error) { + kobject_put(&fs_devs->fsid_kobj); + return error; + } + + return 0; }
int btrfs_sysfs_add_mounted(struct btrfs_fs_info *fs_info)