Add a pointer to ima_namespace to the user_namespace and initialize
the init_user_ns with a pointer to init_ima_ns. We need a pointer from
the user namespace to its associated IMA namespace since IMA namespaces
are piggybacking on user namespaces.
Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
Acked-by: Christian Brauner <brauner@xxxxxxxxxx>
Reviewed-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>
---
v13:
- Added comment to ima_namespace pointer in user_namespace structure
following Serge's suggestion
v11:
- Added lost A-b from Christian back
- Added sentence to patch description explaining why we need the pointer
v9:
- Deferred implementation of ima_ns_from_user_ns() to later patch
---
include/linux/ima.h | 2 ++
include/linux/user_namespace.h | 9 +++++++++
kernel/user.c | 4 ++++
3 files changed, 15 insertions(+)
diff --git a/include/linux/ima.h b/include/linux/ima.h
index 5a0b2a285a18..2038e2e2a88d 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -14,6 +14,8 @@
#include <crypto/hash_info.h>
struct linux_binprm;
+extern struct ima_namespace init_ima_ns;
+
#ifdef CONFIG_IMA
extern enum hash_algo ima_get_current_hash_algo(void);
extern int ima_bprm_check(struct linux_binprm *bprm);
diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
index 45f09bec02c4..c4b4f07b642e 100644
--- a/include/linux/user_namespace.h
+++ b/include/linux/user_namespace.h
@@ -36,6 +36,7 @@ struct uid_gid_map { /* 64 bytes -- 1 cache line */
#define USERNS_INIT_FLAGS USERNS_SETGROUPS_ALLOWED
struct ucounts;
+struct ima_namespace;
enum ucount_type {
UCOUNT_USER_NAMESPACES,
@@ -102,6 +103,14 @@ struct user_namespace {
struct ucounts *ucounts;
long ucount_max[UCOUNT_COUNTS];
long rlimit_max[UCOUNT_RLIMIT_COUNTS];
+#ifdef CONFIG_IMA_NS
+ /* Pointer to ima_ns which this user_ns created. Can be null. IMA's
+ * file access checks will walk the userns->parent chain and check
+ * against all active ima_ns's. Note that when the user_ns is
+ * freed, the ima_ns is guaranteed to be free-able.
+ */
+ struct ima_namespace *ima_ns;
+#endif
} __randomize_layout;
struct ucounts {
diff --git a/kernel/user.c b/kernel/user.c
index d667debeafd6..2c1419215ecc 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -19,6 +19,7 @@
#include <linux/export.h>
#include <linux/user_namespace.h>
#include <linux/proc_ns.h>
+#include <linux/ima.h>
/*
* userns count is 1 for root user, 1 for init_uts_ns,
@@ -67,6 +68,9 @@ struct user_namespace init_user_ns = {
.keyring_name_list = LIST_HEAD_INIT(init_user_ns.keyring_name_list),
.keyring_sem = __RWSEM_INITIALIZER(init_user_ns.keyring_sem),
#endif
+#ifdef CONFIG_IMA_NS
+ .ima_ns = &init_ima_ns,
+#endif
};
EXPORT_SYMBOL_GPL(init_user_ns);
--
2.37.3
