From 13bcc6a2853435bb5dad368bcbaa9d2a5b9c0ac4 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Sat, 16 Jul 2016 15:22:55 -0500 Subject: [PATCH] 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: Kees Cook Acked-by: Serge Hallyn Signed-off-by: "Eric W. Biederman" --- fs/proc/proc_sysctl.c | 14 +++++++------- include/linux/sysctl.h | 3 +-- net/sysctl_net.c | 4 ++-- 3 files changed, 10 insertions(+), 11 deletions(-) diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index 1b93650dda2f..a80acdfbe180 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -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); diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 697e160c78d0..f166ca0203e2 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -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); }; diff --git a/net/sysctl_net.c b/net/sysctl_net.c index 46a71c701e7c..ba9b5d1a31df 100644 --- a/net/sysctl_net.c +++ b/net/sysctl_net.c @@ -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 ¤t->nsproxy->net_ns->sysctls; } static int is_seen(struct ctl_table_set *set) -- 2.20.1