[PATCH] securityfs: fix missing of d_delete() in securityfs_remove()

[alexjlzheng@gmail.com]

From: Jinliang Zheng <alexjlzheng@tencent.com>

Consider the following module code:

  static struct dentry *dentry;

  static int __init securityfs_test_init(void)
  {
          dentry = securityfs_create_dir("standon", NULL);
          return PTR_ERR(dentry);
  }

  static void __exit securityfs_test_exit(void)
  {
          securityfs_remove(dentry);
  }

  module_init(securityfs_test_init);
  module_exit(securityfs_test_exit);

and then:

  insmod /path/to/thismodule
  cd /sys/kernel/security/standon     <- we hold 'standon'
  rmmod thismodule                    <- 'standon' don't go away
  insmod /path/to/thismodule          <- Failed: File exists!

Fix this by adding d_delete() in securityfs_remove().

Fixes: b67dbf9d4c198 ("[PATCH] add securityfs for all LSMs to use")
Signed-off-by: Jinliang Zheng <alexjlzheng@tencent.com>
Cc: <stable@vger.kernel.org>
---
 security/inode.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/security/inode.c b/security/inode.c
index da3ab44c8e57..d99baf26350a 100644
--- a/security/inode.c
+++ b/security/inode.c
@@ -306,6 +306,7 @@ void securityfs_remove(struct dentry *dentry)
 			simple_rmdir(dir, dentry);
 		else
 			simple_unlink(dir, dentry);
+		d_delete(dentry);
 		dput(dentry);
 	}
 	inode_unlock(dir);
-- 
2.49.0