btrfs: fix double free in create_space_info() error path

commit 3f487be upstream.

When kobject_init_and_add() fails, the call chain is:

create_space_info()
-> btrfs_sysfs_add_space_info_type()
-> kobject_init_and_add()
-> failure
-> kobject_put(&space_info->kobj)
-> space_info_release()
-> kfree(space_info)

Then control returns to create_space_info():

btrfs_sysfs_add_space_info_type() returns error
-> goto out_free
-> kfree(space_info)

This causes a double free.

Keep the direct kfree(space_info) for the earlier failure path, but
after btrfs_sysfs_add_space_info_type() has called kobject_put(), let
the kobject release callback handle the cleanup.

Fixes: a11224a ("btrfs: fix memory leaks in create_space_info() error paths")
CC: stable@vger.kernel.org # 6.19+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: lgs2513

fs/btrfs/space-info.c

@@ -293,7 +293,7 @@ static int create_space_info(struct btrfs_fs_info *info, u64 flags)
 
 	ret = btrfs_sysfs_add_space_info_type(info, space_info);
 	if (ret)
-		goto out_free;
+		return ret;
 
 	list_add(&space_info->list, &info->space_info);
 	if (flags & BTRFS_BLOCK_GROUP_DATA)