diff options
author | Eric W. Biederman <ebiederm@xmission.com> | 2011-11-16 21:52:53 -0800 |
---|---|---|
committer | Eric W. Biederman <ebiederm@xmission.com> | 2012-04-07 16:55:52 -0700 |
commit | 0093ccb68f3753c0ba4d74c89d7e0f444b8d6123 (patch) | |
tree | a6fc0ea2a6dfc338fa8fc7126005f40109ef8dce /kernel | |
parent | c4a4d603796c727b9555867571f89483be9c565e (diff) | |
download | linux-stable-0093ccb68f3753c0ba4d74c89d7e0f444b8d6123.tar.gz linux-stable-0093ccb68f3753c0ba4d74c89d7e0f444b8d6123.tar.bz2 linux-stable-0093ccb68f3753c0ba4d74c89d7e0f444b8d6123.zip |
cred: Refcount the user_ns pointed to by the cred.
struct user_struct will shortly loose it's user_ns reference
so make the cred user_ns reference a proper reference complete
with reference counting.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/cred.c | 8 | ||||
-rw-r--r-- | kernel/user_namespace.c | 8 |
2 files changed, 8 insertions, 8 deletions
diff --git a/kernel/cred.c b/kernel/cred.c index 97b36eeca4c9..7a0d80669886 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -148,6 +148,7 @@ static void put_cred_rcu(struct rcu_head *rcu) if (cred->group_info) put_group_info(cred->group_info); free_uid(cred->user); + put_user_ns(cred->user_ns); kmem_cache_free(cred_jar, cred); } @@ -303,6 +304,7 @@ struct cred *prepare_creds(void) set_cred_subscribers(new, 0); get_group_info(new->group_info); get_uid(new->user); + get_user_ns(new->user_ns); #ifdef CONFIG_KEYS key_get(new->thread_keyring); @@ -412,11 +414,6 @@ int copy_creds(struct task_struct *p, unsigned long clone_flags) goto error_put; } - /* cache user_ns in cred. Doesn't need a refcount because it will - * stay pinned by cred->user - */ - new->user_ns = new->user->user_ns; - #ifdef CONFIG_KEYS /* new threads get their own thread keyrings if their parent already * had one */ @@ -676,6 +673,7 @@ struct cred *prepare_kernel_cred(struct task_struct *daemon) atomic_set(&new->usage, 1); set_cred_subscribers(new, 0); get_uid(new->user); + get_user_ns(new->user_ns); get_group_info(new->group_info); #ifdef CONFIG_KEYS diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index f084083a0fd3..58bb8781a778 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -24,7 +24,7 @@ static struct kmem_cache *user_ns_cachep __read_mostly; */ int create_user_ns(struct cred *new) { - struct user_namespace *ns; + struct user_namespace *ns, *parent_ns = new->user_ns; struct user_struct *root_user; int n; @@ -57,8 +57,10 @@ int create_user_ns(struct cred *new) #endif /* tgcred will be cleared in our caller bc CLONE_THREAD won't be set */ - /* root_user holds a reference to ns, our reference can be dropped */ - put_user_ns(ns); + /* Leave the reference to our user_ns with the new cred */ + new->user_ns = ns; + + put_user_ns(parent_ns); return 0; } |