Commit 13bcc6a2 authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

sysctl: Stop implicitly passing current into sysctl_table_root.lookup 



Passing nsproxy into sysctl_table_root.lookup was a premature
optimization in attempt to avoid depending on current.  The
directory /proc/self/sys has not appeared and if and when
it does this code will need to be reviewed closely and reworked
anyway.  So remove the premature optimization.

Acked-by: default avatarKees Cook <keescook@chromium.org>
Acked-by: default avatarSerge Hallyn <serge@hallyn.com>
Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
parent 29b4817d

fs/proc/proc_sysctl.c

+7 −7
Original line number Diff line number Diff line
@@ -72,7 +72,7 @@ static DEFINE_SPINLOCK(sysctl_lock); 


static void drop_sysctl_table(struct ctl_table_header *header);

static int sysctl_follow_link(struct ctl_table_header **phead,

	struct ctl_table **pentry, struct nsproxy *namespaces);

	struct ctl_table **pentry);

static int insert_links(struct ctl_table_header *head);

static void put_links(struct ctl_table_header *header);
@@ -319,11 +319,11 @@ static void sysctl_head_finish(struct ctl_table_header *head) 
}



static struct ctl_table_set *

lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)

lookup_header_set(struct ctl_table_root *root)

{

	struct ctl_table_set *set = &root->default_set;

	if (root->lookup)

		set = root->lookup(root, namespaces);

		set = root->lookup(root);

	return set;

}
@@ -491,7 +491,7 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, 
		goto out;



	if (S_ISLNK(p->mode)) {

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

		ret = sysctl_follow_link(&h, &p);

		err = ERR_PTR(ret);

		if (ret)

			goto out;
@@ -659,7 +659,7 @@ static bool proc_sys_link_fill_cache(struct file *file, 


	if (S_ISLNK(table->mode)) {

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

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

		int err = sysctl_follow_link(&head, &table);

		if (err)

			goto out;

	}
@@ -976,7 +976,7 @@ static struct ctl_dir *xlate_dir(struct ctl_table_set *set, struct ctl_dir *dir) 
}



static int sysctl_follow_link(struct ctl_table_header **phead,

	struct ctl_table **pentry, struct nsproxy *namespaces)

	struct ctl_table **pentry)

{

	struct ctl_table_header *head;

	struct ctl_table_root *root;
@@ -988,7 +988,7 @@ static int sysctl_follow_link(struct ctl_table_header **phead, 
	ret = 0;

	spin_lock(&sysctl_lock);

	root = (*pentry)->data;

	set = lookup_header_set(root, namespaces);

	set = lookup_header_set(root);

	dir = xlate_dir(set, (*phead)->parent);

	if (IS_ERR(dir))

		ret = PTR_ERR(dir);

include/linux/sysctl.h

+1 −2
Original line number Diff line number Diff line
@@ -155,8 +155,7 @@ struct ctl_table_set { 


struct ctl_table_root {

	struct ctl_table_set default_set;

	struct ctl_table_set *(*lookup)(struct ctl_table_root *root,

					   struct nsproxy *namespaces);

	struct ctl_table_set *(*lookup)(struct ctl_table_root *root);

	int (*permissions)(struct ctl_table_header *head, struct ctl_table *table);

};

net/sysctl_net.c

+2 −2
Original line number Diff line number Diff line
@@ -27,9 +27,9 @@ 
#endif



static struct ctl_table_set *

net_ctl_header_lookup(struct ctl_table_root *root, struct nsproxy *namespaces)

net_ctl_header_lookup(struct ctl_table_root *root)

{

	return &namespaces->net_ns->sysctls;

	return &current->nsproxy->net_ns->sysctls;

}



static int is_seen(struct ctl_table_set *set)

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