Commit 4e757320 authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

sysctl: Don't call sysctl_follow_link unless we are a link. 



There are no functional changes.  Just code motion to make it
clear that we don't follow a link between sysctl roots unless the
directory entry actually is a link.

Suggested-by: default avatarLucian Adrian Grijincu <lucian.grijincu@gmail.com>
Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
parent 60f126d9

fs/proc/proc_sysctl.c

+12 −12
Original line number Original line Diff line number Diff line
@@ -451,10 +451,12 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, 
	if (!p)

	if (!p)

		goto out;

		goto out;





	if (S_ISLNK(p->mode)) {

		ret = sysctl_follow_link(&h, &p, current->nsproxy);

		ret = sysctl_follow_link(&h, &p, current->nsproxy);

		err = ERR_PTR(ret);

		err = ERR_PTR(ret);

		if (ret)

		if (ret)

			goto out;

			goto out;

	}





	err = ERR_PTR(-ENOMEM);

	err = ERR_PTR(-ENOMEM);

	inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p);

	inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p);
@@ -601,10 +603,12 @@ static int proc_sys_link_fill_cache(struct file *filp, void *dirent, 
	int err, ret = 0;

	int err, ret = 0;

	head = sysctl_head_grab(head);

	head = sysctl_head_grab(head);





	if (S_ISLNK(table->mode)) {

		/* It is not an error if we can not follow the link ignore it */

		/* It is not an error if we can not follow the link ignore it */

		err = sysctl_follow_link(&head, &table, current->nsproxy);

		err = sysctl_follow_link(&head, &table, current->nsproxy);

		if (err)

		if (err)

			goto out;

			goto out;

	}





	ret = proc_sys_fill_cache(filp, dirent, filldir, head, table);

	ret = proc_sys_fill_cache(filp, dirent, filldir, head, table);

out:

out:
@@ -950,10 +954,6 @@ static int sysctl_follow_link(struct ctl_table_header **phead, 
	struct ctl_dir *dir;

	struct ctl_dir *dir;

	int ret;

	int ret;





	/* Get out quickly if not a link */

	if (!S_ISLNK((*pentry)->mode))

		return 0;



	ret = 0;

	ret = 0;

	spin_lock(&sysctl_lock);

	spin_lock(&sysctl_lock);

	root = (*pentry)->data;

	root = (*pentry)->data;