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| author |   David Howells <dhowells@redhat.com> | 2019-06-26 21:02:32 +0100 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2019-06-26 21:02:32 +0100 |
| commit | 0f44e4d976f96c6439da0d6717238efa4b91196e (patch) | |
| tree | 3cec4bc4ef3faa4e61058e3aff066a7bec1c9d37 /kernel | |
| parent | keys: Namespace keyring names (diff) | |
| download | linux-dev-0f44e4d976f96c6439da0d6717238efa4b91196e.tar.xz linux-dev-0f44e4d976f96c6439da0d6717238efa4b91196e.zip | |
keys: Move the user and user-session keyrings to the user_namespace
Move the user and user-session keyrings to the user_namespace struct rather
than pinning them from the user_struct struct. This prevents these
keyrings from propagating across user-namespaces boundaries with regard to
the KEY_SPEC_* flags, thereby making them more useful in a containerised
environment.
The issue is that a single user_struct may be represent UIDs in several
different namespaces.
The way the patch does this is by attaching a 'register keyring' in each
user_namespace and then sticking the user and user-session keyrings into
that. It can then be searched to retrieve them.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jann Horn <jannh@google.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/user.c | 7 | ||||
| -rw-r--r-- | kernel/user_namespace.c | 4 |
2 files changed, 2 insertions, 9 deletions
diff --git a/kernel/user.c b/kernel/user.c index 50979fd1b7aa..f8519b62cf9a 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -64,10 +64,7 @@ struct user_namespace init_user_ns = { .flags = USERNS_INIT_FLAGS, #ifdef CONFIG_KEYS .keyring_name_list = LIST_HEAD_INIT(init_user_ns.keyring_name_list), -#endif -#ifdef CONFIG_PERSISTENT_KEYRINGS - .persistent_keyring_register_sem = - __RWSEM_INITIALIZER(init_user_ns.persistent_keyring_register_sem), + .keyring_sem = __RWSEM_INITIALIZER(init_user_ns.keyring_sem), #endif }; EXPORT_SYMBOL_GPL(init_user_ns); @@ -143,8 +140,6 @@ static void free_user(struct user_struct *up, unsigned long flags) { uid_hash_remove(up); spin_unlock_irqrestore(&uidhash_lock, flags); - key_put(up->uid_keyring); - key_put(up->session_keyring); kmem_cache_free(uid_cachep, up); } diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index bda6e890ad88..c87c2ecc7085 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -135,9 +135,7 @@ int create_user_ns(struct cred *new) #ifdef CONFIG_KEYS INIT_LIST_HEAD(&ns->keyring_name_list); -#endif -#ifdef CONFIG_PERSISTENT_KEYRINGS - init_rwsem(&ns->persistent_keyring_register_sem); + init_rwsem(&ns->keyring_sem); #endif ret = -ENOMEM; if (!setup_userns_sysctls(ns)) |