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-rw-r--r--include/linux/sched.h1
-rw-r--r--kernel/user.c26
-rw-r--r--kernel/user_namespace.c2
3 files changed, 27 insertions, 2 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 6239bc2c2baa..5445eaec6908 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1472,6 +1472,7 @@ static inline struct user_struct *get_uid(struct user_struct *u)
}
extern void free_uid(struct user_struct *);
extern void switch_uid(struct user_struct *);
+extern void release_uids(struct user_namespace *ns);
#include <asm/current.h>
diff --git a/kernel/user.c b/kernel/user.c
index add57c7e4c07..9ca2848fc356 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -62,7 +62,7 @@ static inline void uid_hash_insert(struct user_struct *up, struct hlist_head *ha
static inline void uid_hash_remove(struct user_struct *up)
{
- hlist_del(&up->uidhash_node);
+ hlist_del_init(&up->uidhash_node);
}
static inline struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent)
@@ -199,6 +199,30 @@ void switch_uid(struct user_struct *new_user)
suid_keys(current);
}
+void release_uids(struct user_namespace *ns)
+{
+ int i;
+ unsigned long flags;
+ struct hlist_head *head;
+ struct hlist_node *nd;
+
+ spin_lock_irqsave(&uidhash_lock, flags);
+ /*
+ * collapse the chains so that the user_struct-s will
+ * be still alive, but not in hashes. subsequent free_uid()
+ * will free them.
+ */
+ for (i = 0; i < UIDHASH_SZ; i++) {
+ head = ns->uidhash_table + i;
+ while (!hlist_empty(head)) {
+ nd = head->first;
+ hlist_del_init(nd);
+ }
+ }
+ spin_unlock_irqrestore(&uidhash_lock, flags);
+
+ free_uid(ns->root_user);
+}
static int __init uid_cache_init(void)
{
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index e7ba1bf8457c..7af90fc4f0fd 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -81,7 +81,7 @@ void free_user_ns(struct kref *kref)
struct user_namespace *ns;
ns = container_of(kref, struct user_namespace, kref);
- free_uid(ns->root_user);
+ release_uids(ns);
kfree(ns);
}