Re: [PATCH v1 1/1] Add Trusted Path Execution as a stackable LSM

From: Al Viro
Date: Sat Jun 03 2017 - 02:34:10 EST


On Sat, Jun 03, 2017 at 01:53:51AM -0400, Matt Brown wrote:

> +static int tpe_bprm_set_creds(struct linux_binprm *bprm)
> +{
> + struct file *file = bprm->file;
> + struct inode *inode = d_backing_inode(file->f_path.dentry->d_parent);
> + struct inode *file_inode = d_backing_inode(file->f_path.dentry);

Bloody wonderful. Do tell, what *does* prevent a race with rename(2) here,
somehow making sure that your 'inode' won't get freed right under you?