Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8cb7104d authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'configfs-for-5.2-2' of git://git.infradead.org/users/hch/configfs 

Pull configs fix from Christoph Hellwig:

 - fix a use after free in configfs_d_iput (Sahitya Tummala)

* tag 'configfs-for-5.2-2' of git://git.infradead.org/users/hch/configfs:
  configfs: Fix use-after-free when accessing sd->s_dentry
parents c5ba1712 f6122ed2

fs/configfs/dir.c

+6 −8
Original line number Diff line number Diff line
@@ -58,15 +58,13 @@ static void configfs_d_iput(struct dentry * dentry, 
	if (sd) {

		/* Coordinate with configfs_readdir */

		spin_lock(&configfs_dirent_lock);

		/* Coordinate with configfs_attach_attr where will increase

		 * sd->s_count and update sd->s_dentry to new allocated one.

		 * Only set sd->dentry to null when this dentry is the only

		 * sd owner.

		 * If not do so, configfs_d_iput may run just after

		 * configfs_attach_attr and set sd->s_dentry to null

		 * even it's still in use.

		/*

		 * Set sd->s_dentry to null only when this dentry is the one

		 * that is going to be killed.  Otherwise configfs_d_iput may

		 * run just after configfs_attach_attr and set sd->s_dentry to

		 * NULL even it's still in use.

		 */

		if (atomic_read(&sd->s_count) <= 2)

		if (sd->s_dentry == dentry)

			sd->s_dentry = NULL;



		spin_unlock(&configfs_dirent_lock);