Implement an IMA namespace data structure that gets created alongside a
user namespace with CLONE_NEWUSER. This lays down the foundation for
namespacing the different aspects of IMA (eg. IMA-audit, IMA-measurement,
IMA-appraisal).
Signed-off-by: Stefan Berger <[email protected]>
Suggested-by: James Bottomley <[email protected]>
---
include/linux/ima.h | 59 +++++++++++++++++
include/linux/user_namespace.h | 4 ++
init/Kconfig | 10 +++
kernel/user.c | 9 ++-
kernel/user_namespace.c | 16 +++++
security/integrity/ima/Makefile | 3 +-
security/integrity/ima/ima.h | 4 ++
security/integrity/ima/ima_init.c | 4 ++
security/integrity/ima/ima_init_ima_ns.c | 32 +++++++++
security/integrity/ima/ima_ns.c | 82 ++++++++++++++++++++++++
10 files changed, 221 insertions(+), 2 deletions(-)
create mode 100644 security/integrity/ima/ima_init_ima_ns.c
create mode 100644 security/integrity/ima/ima_ns.c
diff --git a/include/linux/ima.h b/include/linux/ima.h
index b6ab66a546ae..86d126b9ff2f 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -11,6 +11,7 @@
#include <linux/fs.h>
#include <linux/security.h>
#include <linux/kexec.h>
+#include <linux/user_namespace.h>
#include <crypto/hash_info.h>
struct linux_binprm;
@@ -210,6 +211,64 @@ static inline int ima_inode_removexattr(struct dentry *dentry,
}
#endif /* CONFIG_IMA_APPRAISE */
+struct ima_namespace {
+ struct kref kref;
+ struct user_namespace *user_ns;
+};
+
+extern struct ima_namespace init_ima_ns;
+
+#ifdef CONFIG_IMA_NS
+
+void free_ima_ns(struct kref *kref);
+
+static inline struct ima_namespace *get_ima_ns(struct ima_namespace *ns)
+{
+ if (ns)
+ kref_get(&ns->kref);
+
+ return ns;
+}
+
+static inline void put_ima_ns(struct ima_namespace *ns)
+{
+ if (ns) {
+ pr_debug("DEREF ima_ns: 0x%p ctr: %d\n", ns, kref_read(&ns->kref));
+ kref_put(&ns->kref, free_ima_ns);
+ }
+}
+
+struct ima_namespace *copy_ima_ns(struct ima_namespace *old_ns,
+ struct user_namespace *user_ns);
+
+static inline struct ima_namespace *get_current_ns(void)
+{
+ return current_user_ns()->ima_ns;
+}
+
+#else
+
+static inline struct ima_namespace *get_ima_ns(struct ima_namespace *ns)
+{
+ return ns;
+}
+
+static inline void put_ima_ns(struct ima_namespace *ns)
+{
+}
+
+static inline struct ima_namespace *copy_ima_ns(struct ima_namespace *old_ns,
+ struct user_namespace *user_ns)
+{
+ return old_ns;
+}
+
+static inline struct ima_namespace *get_current_ns(void)
+{
+ return &init_ima_ns;
+}
+#endif /* CONFIG_IMA_NS */
+
#if defined(CONFIG_IMA_APPRAISE) && defined(CONFIG_INTEGRITY_TRUSTED_KEYRING)
extern bool ima_appraise_signature(enum kernel_read_file_id func);
#else
diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
index 33a4240e6a6f..5249db04d62b 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,
@@ -99,6 +100,9 @@ struct user_namespace {
#endif
struct ucounts *ucounts;
long ucount_max[UCOUNT_COUNTS];
+#ifdef CONFIG_IMA
+ struct ima_namespace *ima_ns;
+#endif
} __randomize_layout;
struct ucounts {
diff --git a/init/Kconfig b/init/Kconfig
index 11f8a845f259..27890607e8cb 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1242,6 +1242,16 @@ config NET_NS
Allow user space to create what appear to be multiple instances
of the network stack.
+config IMA_NS
+ bool "IMA namespace"
+ depends on USER_NS
+ depends on IMA
+ default y
+ help
+ Allow the creation of IMA namespaces for each user namespace.
+ Namespaced IMA enables having IMA features work separately
+ in each IMA namespace.
+
endif # NAMESPACES
config CHECKPOINT_RESTORE
diff --git a/kernel/user.c b/kernel/user.c
index e2cf8c22b539..b5dc803a033d 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -20,6 +20,10 @@
#include <linux/user_namespace.h>
#include <linux/proc_ns.h>
+#ifdef CONFIG_IMA
+extern struct ima_namespace init_ima_ns;
+#endif
+
/*
* userns count is 1 for root user, 1 for init_uts_ns,
* and 1 for... ?
@@ -55,7 +59,7 @@ struct user_namespace init_user_ns = {
},
},
},
- .ns.count = REFCOUNT_INIT(3),
+ .ns.count = REFCOUNT_INIT(4),
.owner = GLOBAL_ROOT_UID,
.group = GLOBAL_ROOT_GID,
.ns.inum = PROC_USER_INIT_INO,
@@ -67,6 +71,9 @@ 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
+ .ima_ns = &init_ima_ns,
+#endif
};
EXPORT_SYMBOL_GPL(init_user_ns);
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 6b2e3ca7ee99..c26885343b19 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -20,6 +20,7 @@
#include <linux/fs_struct.h>
#include <linux/bsearch.h>
#include <linux/sort.h>
+#include <linux/ima.h>
static struct kmem_cache *user_ns_cachep __read_mostly;
static DEFINE_MUTEX(userns_state_mutex);
@@ -141,8 +142,20 @@ int create_user_ns(struct cred *new)
if (!setup_userns_sysctls(ns))
goto fail_keyring;
+#if CONFIG_IMA
+ ns->ima_ns = copy_ima_ns(parent_ns->ima_ns, ns);
+ if (IS_ERR(ns->ima_ns)) {
+ ret = PTR_ERR(ns->ima_ns);
+ goto fail_userns_sysctls;
+ }
+#endif
+
set_cred_user_ns(new, ns);
return 0;
+#if CONFIG_IMA
+fail_userns_sysctls:
+ retire_userns_sysctls(ns);
+#endif
fail_keyring:
#ifdef CONFIG_PERSISTENT_KEYRINGS
key_put(ns->persistent_keyring_register);
@@ -196,6 +209,9 @@ static void free_user_ns(struct work_struct *work)
kfree(ns->projid_map.forward);
kfree(ns->projid_map.reverse);
}
+#ifdef CONFIG_IMA
+ put_ima_ns(ns->ima_ns);
+#endif
retire_userns_sysctls(ns);
key_free_user_ns(ns);
ns_free_inum(&ns->ns);
diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
index 2499f2485c04..b86a35fbed60 100644
--- a/security/integrity/ima/Makefile
+++ b/security/integrity/ima/Makefile
@@ -7,13 +7,14 @@
obj-$(CONFIG_IMA) += ima.o
ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
- ima_policy.o ima_template.o ima_template_lib.o
+ ima_policy.o ima_template.o ima_template_lib.o ima_init_ima_ns.o
ima-$(CONFIG_IMA_APPRAISE) += ima_appraise.o
ima-$(CONFIG_IMA_APPRAISE_MODSIG) += ima_modsig.o
ima-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o
ima-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o
ima-$(CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS) += ima_asymmetric_keys.o
ima-$(CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS) += ima_queue_keys.o
+ima-$(CONFIG_IMA_NS) += ima_ns.o
ifeq ($(CONFIG_EFI),y)
ima-$(CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT) += ima_efi.o
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index be965a8715e4..2f8adf383054 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -418,6 +418,10 @@ static inline void ima_free_modsig(struct modsig *modsig)
}
#endif /* CONFIG_IMA_APPRAISE_MODSIG */
+int ima_ns_init(void);
+struct ima_namespace;
+int ima_init_namespace(struct ima_namespace *ns);
+
/* LSM based policy rules require audit */
#ifdef CONFIG_IMA_LSM_RULES
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index b26fa67476b4..f6ae4557a0da 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -120,6 +120,10 @@ int __init ima_init(void)
{
int rc;
+ rc = ima_ns_init();
+ if (rc)
+ return rc;
+
ima_tpm_chip = tpm_default_chip();
if (!ima_tpm_chip)
pr_info("No TPM chip found, activating TPM-bypass!\n");
diff --git a/security/integrity/ima/ima_init_ima_ns.c b/security/integrity/ima/ima_init_ima_ns.c
new file mode 100644
index 000000000000..12723d77fe17
--- /dev/null
+++ b/security/integrity/ima/ima_init_ima_ns.c
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2016-2018 IBM Corporation
+ * Author:
+ * Yuqiong Sun <[email protected]>
+ * Stefan Berger <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ */
+
+#include <linux/export.h>
+#include <linux/user_namespace.h>
+#include <linux/ima.h>
+#include <linux/proc_ns.h>
+
+int ima_init_namespace(struct ima_namespace *ns)
+{
+ return 0;
+}
+
+int __init ima_ns_init(void)
+{
+ return ima_init_namespace(&init_ima_ns);
+}
+
+struct ima_namespace init_ima_ns = {
+ .kref = KREF_INIT(1),
+ .user_ns = &init_user_ns,
+};
+EXPORT_SYMBOL(init_ima_ns);
diff --git a/security/integrity/ima/ima_ns.c b/security/integrity/ima/ima_ns.c
new file mode 100644
index 000000000000..9a782c08c34e
--- /dev/null
+++ b/security/integrity/ima/ima_ns.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2016-2018 IBM Corporation
+ * Author:
+ * Yuqiong Sun <[email protected]>
+ * Stefan Berger <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ */
+
+#include <linux/kref.h>
+#include <linux/slab.h>
+#include <linux/ima.h>
+#include <linux/mount.h>
+#include <linux/proc_ns.h>
+#include <linux/lsm_hooks.h>
+
+#include "ima.h"
+
+static struct kmem_cache *imans_cachep;
+
+static struct ima_namespace *create_ima_ns(struct user_namespace *user_ns)
+{
+ struct ima_namespace *ns;
+ int err;
+
+ ns = kmem_cache_zalloc(imans_cachep, GFP_KERNEL);
+ if (!ns)
+ return ERR_PTR(-ENOMEM);
+ pr_debug("NEW ima_ns: 0x%p\n", ns);
+
+ kref_init(&ns->kref);
+ ns->user_ns = user_ns;
+
+ err = ima_init_namespace(ns);
+ if (err)
+ goto fail_free;
+
+ return ns;
+
+fail_free:
+ kmem_cache_free(imans_cachep, ns);
+
+ return ERR_PTR(err);
+}
+
+/**
+ * Copy an ima namespace - create a new one
+ *
+ * @old_ns: old ima namespace to clone
+ * @user_ns: User namespace
+ */
+struct ima_namespace *copy_ima_ns(struct ima_namespace *old_ns,
+ struct user_namespace *user_ns)
+{
+ return create_ima_ns(user_ns);
+}
+
+static void destroy_ima_ns(struct ima_namespace *ns)
+{
+ pr_debug("DESTROY ima_ns: 0x%p\n", ns);
+ kmem_cache_free(imans_cachep, ns);
+}
+
+void free_ima_ns(struct kref *kref)
+{
+ struct ima_namespace *ns;
+
+ ns = container_of(kref, struct ima_namespace, kref);
+ BUG_ON(ns == &init_ima_ns);
+
+ destroy_ima_ns(ns);
+}
+
+static int __init imans_cache_init(void)
+{
+ imans_cachep = KMEM_CACHE(ima_namespace, SLAB_PANIC);
+ return 0;
+}
+subsys_initcall(imans_cache_init)
--
2.31.1
On Tue, Dec 07, 2021 at 03:21:12PM -0500, Stefan Berger wrote:
> Implement an IMA namespace data structure that gets created alongside a
> user namespace with CLONE_NEWUSER. This lays down the foundation for
> namespacing the different aspects of IMA (eg. IMA-audit, IMA-measurement,
> IMA-appraisal).
>
> Signed-off-by: Stefan Berger <[email protected]>
> Suggested-by: James Bottomley <[email protected]>
> ---
> include/linux/ima.h | 59 +++++++++++++++++
> include/linux/user_namespace.h | 4 ++
> init/Kconfig | 10 +++
> kernel/user.c | 9 ++-
> kernel/user_namespace.c | 16 +++++
> security/integrity/ima/Makefile | 3 +-
> security/integrity/ima/ima.h | 4 ++
> security/integrity/ima/ima_init.c | 4 ++
> security/integrity/ima/ima_init_ima_ns.c | 32 +++++++++
> security/integrity/ima/ima_ns.c | 82 ++++++++++++++++++++++++
> 10 files changed, 221 insertions(+), 2 deletions(-)
> create mode 100644 security/integrity/ima/ima_init_ima_ns.c
> create mode 100644 security/integrity/ima/ima_ns.c
>
> diff --git a/include/linux/ima.h b/include/linux/ima.h
> index b6ab66a546ae..86d126b9ff2f 100644
> --- a/include/linux/ima.h
> +++ b/include/linux/ima.h
> @@ -11,6 +11,7 @@
> #include <linux/fs.h>
> #include <linux/security.h>
> #include <linux/kexec.h>
> +#include <linux/user_namespace.h>
> #include <crypto/hash_info.h>
> struct linux_binprm;
>
> @@ -210,6 +211,64 @@ static inline int ima_inode_removexattr(struct dentry *dentry,
> }
> #endif /* CONFIG_IMA_APPRAISE */
>
> +struct ima_namespace {
> + struct kref kref;
> + struct user_namespace *user_ns;
> +};
> +
> +extern struct ima_namespace init_ima_ns;
> +
> +#ifdef CONFIG_IMA_NS
> +
> +void free_ima_ns(struct kref *kref);
> +
> +static inline struct ima_namespace *get_ima_ns(struct ima_namespace *ns)
> +{
> + if (ns)
> + kref_get(&ns->kref);
> +
> + return ns;
> +}
> +
> +static inline void put_ima_ns(struct ima_namespace *ns)
> +{
> + if (ns) {
> + pr_debug("DEREF ima_ns: 0x%p ctr: %d\n", ns, kref_read(&ns->kref));
> + kref_put(&ns->kref, free_ima_ns);
> + }
> +}
> +
> +struct ima_namespace *copy_ima_ns(struct ima_namespace *old_ns,
> + struct user_namespace *user_ns);
> +
> +static inline struct ima_namespace *get_current_ns(void)
> +{
> + return current_user_ns()->ima_ns;
> +}
> +
> +#else
> +
> +static inline struct ima_namespace *get_ima_ns(struct ima_namespace *ns)
> +{
> + return ns;
> +}
> +
> +static inline void put_ima_ns(struct ima_namespace *ns)
> +{
> +}
> +
> +static inline struct ima_namespace *copy_ima_ns(struct ima_namespace *old_ns,
> + struct user_namespace *user_ns)
> +{
> + return old_ns;
> +}
> +
> +static inline struct ima_namespace *get_current_ns(void)
> +{
> + return &init_ima_ns;
> +}
> +#endif /* CONFIG_IMA_NS */
> +
> #if defined(CONFIG_IMA_APPRAISE) && defined(CONFIG_INTEGRITY_TRUSTED_KEYRING)
> extern bool ima_appraise_signature(enum kernel_read_file_id func);
> #else
> diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
> index 33a4240e6a6f..5249db04d62b 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,
> @@ -99,6 +100,9 @@ struct user_namespace {
> #endif
> struct ucounts *ucounts;
> long ucount_max[UCOUNT_COUNTS];
> +#ifdef CONFIG_IMA
> + struct ima_namespace *ima_ns;
> +#endif
> } __randomize_layout;
>
> struct ucounts {
> diff --git a/init/Kconfig b/init/Kconfig
> index 11f8a845f259..27890607e8cb 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -1242,6 +1242,16 @@ config NET_NS
> Allow user space to create what appear to be multiple instances
> of the network stack.
>
> +config IMA_NS
> + bool "IMA namespace"
> + depends on USER_NS
> + depends on IMA
> + default y
> + help
> + Allow the creation of IMA namespaces for each user namespace.
> + Namespaced IMA enables having IMA features work separately
> + in each IMA namespace.
> +
> endif # NAMESPACES
>
> config CHECKPOINT_RESTORE
> diff --git a/kernel/user.c b/kernel/user.c
> index e2cf8c22b539..b5dc803a033d 100644
> --- a/kernel/user.c
> +++ b/kernel/user.c
> @@ -20,6 +20,10 @@
> #include <linux/user_namespace.h>
> #include <linux/proc_ns.h>
>
> +#ifdef CONFIG_IMA
> +extern struct ima_namespace init_ima_ns;
> +#endif
> +
> /*
> * userns count is 1 for root user, 1 for init_uts_ns,
> * and 1 for... ?
> @@ -55,7 +59,7 @@ struct user_namespace init_user_ns = {
> },
> },
> },
> - .ns.count = REFCOUNT_INIT(3),
> + .ns.count = REFCOUNT_INIT(4),
> .owner = GLOBAL_ROOT_UID,
> .group = GLOBAL_ROOT_GID,
> .ns.inum = PROC_USER_INIT_INO,
> @@ -67,6 +71,9 @@ 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
> + .ima_ns = &init_ima_ns,
> +#endif
> };
> EXPORT_SYMBOL_GPL(init_user_ns);
>
> diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
> index 6b2e3ca7ee99..c26885343b19 100644
> --- a/kernel/user_namespace.c
> +++ b/kernel/user_namespace.c
> @@ -20,6 +20,7 @@
> #include <linux/fs_struct.h>
> #include <linux/bsearch.h>
> #include <linux/sort.h>
> +#include <linux/ima.h>
>
> static struct kmem_cache *user_ns_cachep __read_mostly;
> static DEFINE_MUTEX(userns_state_mutex);
> @@ -141,8 +142,20 @@ int create_user_ns(struct cred *new)
> if (!setup_userns_sysctls(ns))
> goto fail_keyring;
>
> +#if CONFIG_IMA
> + ns->ima_ns = copy_ima_ns(parent_ns->ima_ns, ns);
> + if (IS_ERR(ns->ima_ns)) {
> + ret = PTR_ERR(ns->ima_ns);
> + goto fail_userns_sysctls;
> + }
> +#endif
> +
> set_cred_user_ns(new, ns);
> return 0;
> +#if CONFIG_IMA
> +fail_userns_sysctls:
> + retire_userns_sysctls(ns);
> +#endif
> fail_keyring:
> #ifdef CONFIG_PERSISTENT_KEYRINGS
> key_put(ns->persistent_keyring_register);
> @@ -196,6 +209,9 @@ static void free_user_ns(struct work_struct *work)
> kfree(ns->projid_map.forward);
> kfree(ns->projid_map.reverse);
> }
> +#ifdef CONFIG_IMA
> + put_ima_ns(ns->ima_ns);
> +#endif
> retire_userns_sysctls(ns);
> key_free_user_ns(ns);
> ns_free_inum(&ns->ns);
> diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
> index 2499f2485c04..b86a35fbed60 100644
> --- a/security/integrity/ima/Makefile
> +++ b/security/integrity/ima/Makefile
> @@ -7,13 +7,14 @@
> obj-$(CONFIG_IMA) += ima.o
>
> ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
> - ima_policy.o ima_template.o ima_template_lib.o
> + ima_policy.o ima_template.o ima_template_lib.o ima_init_ima_ns.o
> ima-$(CONFIG_IMA_APPRAISE) += ima_appraise.o
> ima-$(CONFIG_IMA_APPRAISE_MODSIG) += ima_modsig.o
> ima-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o
> ima-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o
> ima-$(CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS) += ima_asymmetric_keys.o
> ima-$(CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS) += ima_queue_keys.o
> +ima-$(CONFIG_IMA_NS) += ima_ns.o
>
> ifeq ($(CONFIG_EFI),y)
> ima-$(CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT) += ima_efi.o
> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
> index be965a8715e4..2f8adf383054 100644
> --- a/security/integrity/ima/ima.h
> +++ b/security/integrity/ima/ima.h
> @@ -418,6 +418,10 @@ static inline void ima_free_modsig(struct modsig *modsig)
> }
> #endif /* CONFIG_IMA_APPRAISE_MODSIG */
>
> +int ima_ns_init(void);
> +struct ima_namespace;
> +int ima_init_namespace(struct ima_namespace *ns);
> +
> /* LSM based policy rules require audit */
> #ifdef CONFIG_IMA_LSM_RULES
>
> diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
> index b26fa67476b4..f6ae4557a0da 100644
> --- a/security/integrity/ima/ima_init.c
> +++ b/security/integrity/ima/ima_init.c
> @@ -120,6 +120,10 @@ int __init ima_init(void)
> {
> int rc;
>
> + rc = ima_ns_init();
> + if (rc)
> + return rc;
> +
> ima_tpm_chip = tpm_default_chip();
> if (!ima_tpm_chip)
> pr_info("No TPM chip found, activating TPM-bypass!\n");
> diff --git a/security/integrity/ima/ima_init_ima_ns.c b/security/integrity/ima/ima_init_ima_ns.c
> new file mode 100644
> index 000000000000..12723d77fe17
> --- /dev/null
> +++ b/security/integrity/ima/ima_init_ima_ns.c
> @@ -0,0 +1,32 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2016-2018 IBM Corporation
> + * Author:
> + * Yuqiong Sun <[email protected]>
> + * Stefan Berger <[email protected]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation, version 2 of the License.
> + */
> +
> +#include <linux/export.h>
> +#include <linux/user_namespace.h>
> +#include <linux/ima.h>
> +#include <linux/proc_ns.h>
> +
> +int ima_init_namespace(struct ima_namespace *ns)
> +{
> + return 0;
> +}
> +
> +int __init ima_ns_init(void)
> +{
> + return ima_init_namespace(&init_ima_ns);
> +}
> +
> +struct ima_namespace init_ima_ns = {
> + .kref = KREF_INIT(1),
> + .user_ns = &init_user_ns,
> +};
> +EXPORT_SYMBOL(init_ima_ns);
> diff --git a/security/integrity/ima/ima_ns.c b/security/integrity/ima/ima_ns.c
> new file mode 100644
> index 000000000000..9a782c08c34e
> --- /dev/null
> +++ b/security/integrity/ima/ima_ns.c
> @@ -0,0 +1,82 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2016-2018 IBM Corporation
> + * Author:
> + * Yuqiong Sun <[email protected]>
> + * Stefan Berger <[email protected]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation, version 2 of the License.
> + */
> +
> +#include <linux/kref.h>
> +#include <linux/slab.h>
> +#include <linux/ima.h>
> +#include <linux/mount.h>
> +#include <linux/proc_ns.h>
> +#include <linux/lsm_hooks.h>
> +
> +#include "ima.h"
> +
> +static struct kmem_cache *imans_cachep;
> +
> +static struct ima_namespace *create_ima_ns(struct user_namespace *user_ns)
> +{
> + struct ima_namespace *ns;
> + int err;
> +
> + ns = kmem_cache_zalloc(imans_cachep, GFP_KERNEL);
> + if (!ns)
> + return ERR_PTR(-ENOMEM);
> + pr_debug("NEW ima_ns: 0x%p\n", ns);
> +
> + kref_init(&ns->kref);
> + ns->user_ns = user_ns;
> +
> + err = ima_init_namespace(ns);
> + if (err)
> + goto fail_free;
> +
> + return ns;
> +
> +fail_free:
> + kmem_cache_free(imans_cachep, ns);
> +
> + return ERR_PTR(err);
> +}
> +
> +/**
> + * Copy an ima namespace - create a new one
> + *
> + * @old_ns: old ima namespace to clone
> + * @user_ns: User namespace
> + */
> +struct ima_namespace *copy_ima_ns(struct ima_namespace *old_ns,
> + struct user_namespace *user_ns)
> +{
> + return create_ima_ns(user_ns);
> +}
I'd just remove copy_ima_ns() completely and just leave create_ima_ns()
if it's not used anywhere.
> +
> +static void destroy_ima_ns(struct ima_namespace *ns)
> +{
> + pr_debug("DESTROY ima_ns: 0x%p\n", ns);
> + kmem_cache_free(imans_cachep, ns);
> +}
> +
> +void free_ima_ns(struct kref *kref)
> +{
> + struct ima_namespace *ns;
> +
> + ns = container_of(kref, struct ima_namespace, kref);
> + BUG_ON(ns == &init_ima_ns);
I'd not do that. Either
if (ns != &init_ima_ns)
destroy_ima_ns(ns);
so it can be safely called on init_ima_ns or
if (WARN_ON(ns == &init_ima_ns))
return;
> +
> + destroy_ima_ns(ns);
> +}
> +
> +static int __init imans_cache_init(void)
> +{
> + imans_cachep = KMEM_CACHE(ima_namespace, SLAB_PANIC);
> + return 0;
> +}
> +subsys_initcall(imans_cache_init)
> --
> 2.31.1
>
>
On Wed, Dec 08, 2021 at 12:29:18PM +0100, Christian Brauner wrote:
> On Tue, Dec 07, 2021 at 03:21:12PM -0500, Stefan Berger wrote:
> > Implement an IMA namespace data structure that gets created alongside a
> > user namespace with CLONE_NEWUSER. This lays down the foundation for
> > namespacing the different aspects of IMA (eg. IMA-audit, IMA-measurement,
> > IMA-appraisal).
> >
> > Signed-off-by: Stefan Berger <[email protected]>
> > Suggested-by: James Bottomley <[email protected]>
> > ---
> > include/linux/ima.h | 59 +++++++++++++++++
> > include/linux/user_namespace.h | 4 ++
> > init/Kconfig | 10 +++
> > kernel/user.c | 9 ++-
> > kernel/user_namespace.c | 16 +++++
> > security/integrity/ima/Makefile | 3 +-
> > security/integrity/ima/ima.h | 4 ++
> > security/integrity/ima/ima_init.c | 4 ++
> > security/integrity/ima/ima_init_ima_ns.c | 32 +++++++++
> > security/integrity/ima/ima_ns.c | 82 ++++++++++++++++++++++++
> > 10 files changed, 221 insertions(+), 2 deletions(-)
> > create mode 100644 security/integrity/ima/ima_init_ima_ns.c
> > create mode 100644 security/integrity/ima/ima_ns.c
> >
> > diff --git a/include/linux/ima.h b/include/linux/ima.h
> > index b6ab66a546ae..86d126b9ff2f 100644
> > --- a/include/linux/ima.h
> > +++ b/include/linux/ima.h
> > @@ -11,6 +11,7 @@
> > #include <linux/fs.h>
> > #include <linux/security.h>
> > #include <linux/kexec.h>
> > +#include <linux/user_namespace.h>
> > #include <crypto/hash_info.h>
> > struct linux_binprm;
> >
> > @@ -210,6 +211,64 @@ static inline int ima_inode_removexattr(struct dentry *dentry,
> > }
> > #endif /* CONFIG_IMA_APPRAISE */
> >
> > +struct ima_namespace {
> > + struct kref kref;
> > + struct user_namespace *user_ns;
> > +};
> > +
> > +extern struct ima_namespace init_ima_ns;
> > +
> > +#ifdef CONFIG_IMA_NS
> > +
> > +void free_ima_ns(struct kref *kref);
> > +
> > +static inline struct ima_namespace *get_ima_ns(struct ima_namespace *ns)
> > +{
> > + if (ns)
> > + kref_get(&ns->kref);
> > +
> > + return ns;
> > +}
> > +
> > +static inline void put_ima_ns(struct ima_namespace *ns)
> > +{
> > + if (ns) {
> > + pr_debug("DEREF ima_ns: 0x%p ctr: %d\n", ns, kref_read(&ns->kref));
> > + kref_put(&ns->kref, free_ima_ns);
> > + }
> > +}
> > +
> > +struct ima_namespace *copy_ima_ns(struct ima_namespace *old_ns,
> > + struct user_namespace *user_ns);
> > +
> > +static inline struct ima_namespace *get_current_ns(void)
> > +{
> > + return current_user_ns()->ima_ns;
> > +}
> > +
> > +#else
> > +
> > +static inline struct ima_namespace *get_ima_ns(struct ima_namespace *ns)
> > +{
> > + return ns;
> > +}
> > +
> > +static inline void put_ima_ns(struct ima_namespace *ns)
> > +{
> > +}
> > +
> > +static inline struct ima_namespace *copy_ima_ns(struct ima_namespace *old_ns,
> > + struct user_namespace *user_ns)
> > +{
> > + return old_ns;
> > +}
> > +
> > +static inline struct ima_namespace *get_current_ns(void)
> > +{
> > + return &init_ima_ns;
> > +}
> > +#endif /* CONFIG_IMA_NS */
> > +
> > #if defined(CONFIG_IMA_APPRAISE) && defined(CONFIG_INTEGRITY_TRUSTED_KEYRING)
> > extern bool ima_appraise_signature(enum kernel_read_file_id func);
> > #else
> > diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
> > index 33a4240e6a6f..5249db04d62b 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,
> > @@ -99,6 +100,9 @@ struct user_namespace {
> > #endif
> > struct ucounts *ucounts;
> > long ucount_max[UCOUNT_COUNTS];
> > +#ifdef CONFIG_IMA
> > + struct ima_namespace *ima_ns;
> > +#endif
> > } __randomize_layout;
> >
> > struct ucounts {
> > diff --git a/init/Kconfig b/init/Kconfig
> > index 11f8a845f259..27890607e8cb 100644
> > --- a/init/Kconfig
> > +++ b/init/Kconfig
> > @@ -1242,6 +1242,16 @@ config NET_NS
> > Allow user space to create what appear to be multiple instances
> > of the network stack.
> >
> > +config IMA_NS
> > + bool "IMA namespace"
> > + depends on USER_NS
> > + depends on IMA
> > + default y
> > + help
> > + Allow the creation of IMA namespaces for each user namespace.
> > + Namespaced IMA enables having IMA features work separately
> > + in each IMA namespace.
> > +
> > endif # NAMESPACES
> >
> > config CHECKPOINT_RESTORE
> > diff --git a/kernel/user.c b/kernel/user.c
> > index e2cf8c22b539..b5dc803a033d 100644
> > --- a/kernel/user.c
> > +++ b/kernel/user.c
> > @@ -20,6 +20,10 @@
> > #include <linux/user_namespace.h>
> > #include <linux/proc_ns.h>
> >
> > +#ifdef CONFIG_IMA
> > +extern struct ima_namespace init_ima_ns;
> > +#endif
> > +
> > /*
> > * userns count is 1 for root user, 1 for init_uts_ns,
> > * and 1 for... ?
> > @@ -55,7 +59,7 @@ struct user_namespace init_user_ns = {
> > },
> > },
> > },
> > - .ns.count = REFCOUNT_INIT(3),
> > + .ns.count = REFCOUNT_INIT(4),
> > .owner = GLOBAL_ROOT_UID,
> > .group = GLOBAL_ROOT_GID,
> > .ns.inum = PROC_USER_INIT_INO,
> > @@ -67,6 +71,9 @@ 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
> > + .ima_ns = &init_ima_ns,
> > +#endif
> > };
> > EXPORT_SYMBOL_GPL(init_user_ns);
> >
> > diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
> > index 6b2e3ca7ee99..c26885343b19 100644
> > --- a/kernel/user_namespace.c
> > +++ b/kernel/user_namespace.c
> > @@ -20,6 +20,7 @@
> > #include <linux/fs_struct.h>
> > #include <linux/bsearch.h>
> > #include <linux/sort.h>
> > +#include <linux/ima.h>
> >
> > static struct kmem_cache *user_ns_cachep __read_mostly;
> > static DEFINE_MUTEX(userns_state_mutex);
> > @@ -141,8 +142,20 @@ int create_user_ns(struct cred *new)
> > if (!setup_userns_sysctls(ns))
> > goto fail_keyring;
> >
> > +#if CONFIG_IMA
> > + ns->ima_ns = copy_ima_ns(parent_ns->ima_ns, ns);
> > + if (IS_ERR(ns->ima_ns)) {
> > + ret = PTR_ERR(ns->ima_ns);
> > + goto fail_userns_sysctls;
> > + }
> > +#endif
> > +
> > set_cred_user_ns(new, ns);
> > return 0;
> > +#if CONFIG_IMA
> > +fail_userns_sysctls:
> > + retire_userns_sysctls(ns);
> > +#endif
If you rewrite copy_ima_ns() put_ima_ns() a little you can remove all
the ifdefs in here and make this patch tiny.
Make copy_ima_ns() return an int. Afaict, you can remove passing the
parent ima_ns completely but if you have to pass through the
parent_userns.
Then you can initialize new_userns->ima_ns inside of copy_ima_ns() and
the ifdef will only need to be visible inside copy_ima_ns() and not in
create_user_ns(). Similar put_ima_ns() is only called in a single place
namely kernel/user_namespace.c. Make it take a user_namespace argument
and you can remove the ifdef in __put_user_ns() for put_ima_ns() too.
So something -- COMPLETELY UNTESTED -- like the below should work:
diff --git a/include/linux/ima.h b/include/linux/ima.h
index a8017272d78d..dc4aa3027bf4 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -310,16 +310,17 @@ static inline struct ima_namespace *get_ima_ns(struct ima_namespace *ns)
return ns;
}
-static inline void put_ima_ns(struct ima_namespace *ns)
+static inline void put_ima_ns(struct user_namespace *ns)
{
- if (ns) {
- pr_debug("DEREF ima_ns: 0x%p ctr: %d\n", ns, kref_read(&ns->kref));
- kref_put(&ns->kref, free_ima_ns);
+ struct ima_namespace *ima_ns = ns->ima_ns;
+
+ if (im_ns) {
+ pr_debug("DEREF ima_ns: 0x%p ctr: %d\n", im_ns, kref_read(&im_ns->kref));
+ kref_put(&im_ns->kref, free_ima_ns);
}
}
-struct ima_namespace *copy_ima_ns(struct ima_namespace *old_ns,
- struct user_namespace *user_ns);
+int copy_ima_ns(struct user_namespace *user_ns);
static inline struct ima_namespace *get_current_ns(void)
{
@@ -333,14 +334,13 @@ static inline struct ima_namespace *get_ima_ns(struct ima_namespace *ns)
return ns;
}
-static inline void put_ima_ns(struct ima_namespace *ns)
+static inline void put_ima_ns(struct user_namespace *ns)
{
}
-static inline struct ima_namespace *copy_ima_ns(struct ima_namespace *old_ns,
- struct user_namespace *user_ns)
+static inline int copy_ima_ns(struct user_namespace *user_ns)
{
- return old_ns;
+ return 0;
}
static inline struct ima_namespace *get_current_ns(void)
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index c26885343b19..794f027e7677 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -138,24 +138,19 @@ int create_user_ns(struct cred *new)
INIT_LIST_HEAD(&ns->keyring_name_list);
init_rwsem(&ns->keyring_sem);
#endif
+
ret = -ENOMEM;
if (!setup_userns_sysctls(ns))
goto fail_keyring;
-#if CONFIG_IMA
- ns->ima_ns = copy_ima_ns(parent_ns->ima_ns, ns);
- if (IS_ERR(ns->ima_ns)) {
- ret = PTR_ERR(ns->ima_ns);
- goto fail_userns_sysctls;
- }
-#endif
+ ret = create_ima_ns(ns);
+ if (ret)
+ goto fail_sysctls;
set_cred_user_ns(new, ns);
return 0;
-#if CONFIG_IMA
-fail_userns_sysctls:
+fail_sysctls:
retire_userns_sysctls(ns);
-#endif
fail_keyring:
#ifdef CONFIG_PERSISTENT_KEYRINGS
key_put(ns->persistent_keyring_register);
@@ -209,9 +204,7 @@ static void free_user_ns(struct work_struct *work)
kfree(ns->projid_map.forward);
kfree(ns->projid_map.reverse);
}
-#ifdef CONFIG_IMA
- put_ima_ns(ns->ima_ns);
-#endif
+ put_ima_ns(ns);
retire_userns_sysctls(ns);
key_free_user_ns(ns);
ns_free_inum(&ns->ns);
diff --git a/security/integrity/ima/ima_ns.c b/security/integrity/ima/ima_ns.c
index debe863364fd..2bae2c0cdce1 100644
--- a/security/integrity/ima/ima_ns.c
+++ b/security/integrity/ima/ima_ns.c
@@ -21,14 +21,14 @@
static struct kmem_cache *imans_cachep;
-static struct ima_namespace *create_ima_ns(struct user_namespace *user_ns)
+static int create_ima_ns(struct user_namespace *user_ns)
{
struct ima_namespace *ns;
int err;
ns = kmem_cache_zalloc(imans_cachep, GFP_KERNEL);
if (!ns)
- return ERR_PTR(-ENOMEM);
+ return -ENOMEM;
pr_debug("NEW ima_ns: 0x%p\n", ns);
kref_init(&ns->kref);
@@ -44,12 +44,13 @@ static struct ima_namespace *create_ima_ns(struct user_namespace *user_ns)
INIT_LIST_HEAD(&ns->ima_keys);
#endif
- return ns;
+ user_ns->ima_ns = user_ns;
+ return 0;
fail_free:
kmem_cache_free(imans_cachep, ns);
- return ERR_PTR(err);
+ return err;
}
/**
@@ -58,8 +59,7 @@ static struct ima_namespace *create_ima_ns(struct user_namespace *user_ns)
* @old_ns: old ima namespace to clone
* @user_ns: User namespace
*/
-struct ima_namespace *copy_ima_ns(struct ima_namespace *old_ns,
- struct user_namespace *user_ns)
+int copy_ima_ns(struct user_namespace *user_ns)
{
return create_ima_ns(user_ns);
}
On 12/8/21 06:54, Christian Brauner wrote:
> On Wed, Dec 08, 2021 at 12:29:18PM +0100, Christian Brauner wrote:
>> On Tue, Dec 07, 2021 at 03:21:12PM -0500, Stefan Berger wrote:
>>> Implement an IMA namespace data structure that gets created alongside a
>>> user namespace with CLONE_NEWUSER. This lays down the foundation for
>>> namespacing the different aspects of IMA (eg. IMA-audit, IMA-measurement,
>>> IMA-appraisal).
>>>
>>> Signed-off-by: Stefan Berger <[email protected]>
>>> Suggested-by: James Bottomley <[email protected]>
>>> ---
>>> include/linux/ima.h | 59 +++++++++++++++++
>>> include/linux/user_namespace.h | 4 ++
>>> init/Kconfig | 10 +++
>>> kernel/user.c | 9 ++-
>>> kernel/user_namespace.c | 16 +++++
>>> security/integrity/ima/Makefile | 3 +-
>>> security/integrity/ima/ima.h | 4 ++
>>> security/integrity/ima/ima_init.c | 4 ++
>>> security/integrity/ima/ima_init_ima_ns.c | 32 +++++++++
>>> security/integrity/ima/ima_ns.c | 82 ++++++++++++++++++++++++
>>> 10 files changed, 221 insertions(+), 2 deletions(-)
>>> create mode 100644 security/integrity/ima/ima_init_ima_ns.c
>>> create mode 100644 security/integrity/ima/ima_ns.c
>>>
>>> diff --git a/include/linux/ima.h b/include/linux/ima.h
>>> index b6ab66a546ae..86d126b9ff2f 100644
>>> --- a/include/linux/ima.h
>>> +++ b/include/linux/ima.h
>>> @@ -11,6 +11,7 @@
>>> #include <linux/fs.h>
>>> #include <linux/security.h>
>>> #include <linux/kexec.h>
>>> +#include <linux/user_namespace.h>
>>> #include <crypto/hash_info.h>
>>> struct linux_binprm;
>>>
>>> @@ -210,6 +211,64 @@ static inline int ima_inode_removexattr(struct dentry *dentry,
>>> }
>>> #endif /* CONFIG_IMA_APPRAISE */
>>>
>>> +struct ima_namespace {
>>> + struct kref kref;
>>> + struct user_namespace *user_ns;
>>> +};
>>> +
>>> +extern struct ima_namespace init_ima_ns;
>>> +
>>> +#ifdef CONFIG_IMA_NS
>>> +
>>> +void free_ima_ns(struct kref *kref);
>>> +
>>> +static inline struct ima_namespace *get_ima_ns(struct ima_namespace *ns)
>>> +{
>>> + if (ns)
>>> + kref_get(&ns->kref);
>>> +
>>> + return ns;
>>> +}
>>> +
>>> +static inline void put_ima_ns(struct ima_namespace *ns)
>>> +{
>>> + if (ns) {
>>> + pr_debug("DEREF ima_ns: 0x%p ctr: %d\n", ns, kref_read(&ns->kref));
>>> + kref_put(&ns->kref, free_ima_ns);
>>> + }
>>> +}
>>> +
>>> +struct ima_namespace *copy_ima_ns(struct ima_namespace *old_ns,
>>> + struct user_namespace *user_ns);
>>> +
>>> +static inline struct ima_namespace *get_current_ns(void)
>>> +{
>>> + return current_user_ns()->ima_ns;
>>> +}
>>> +
>>> +#else
>>> +
>>> +static inline struct ima_namespace *get_ima_ns(struct ima_namespace *ns)
>>> +{
>>> + return ns;
>>> +}
>>> +
>>> +static inline void put_ima_ns(struct ima_namespace *ns)
>>> +{
>>> +}
>>> +
>>> +static inline struct ima_namespace *copy_ima_ns(struct ima_namespace *old_ns,
>>> + struct user_namespace *user_ns)
>>> +{
>>> + return old_ns;
>>> +}
>>> +
>>> +static inline struct ima_namespace *get_current_ns(void)
>>> +{
>>> + return &init_ima_ns;
>>> +}
>>> +#endif /* CONFIG_IMA_NS */
>>> +
>>> #if defined(CONFIG_IMA_APPRAISE) && defined(CONFIG_INTEGRITY_TRUSTED_KEYRING)
>>> extern bool ima_appraise_signature(enum kernel_read_file_id func);
>>> #else
>>> diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
>>> index 33a4240e6a6f..5249db04d62b 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,
>>> @@ -99,6 +100,9 @@ struct user_namespace {
>>> #endif
>>> struct ucounts *ucounts;
>>> long ucount_max[UCOUNT_COUNTS];
>>> +#ifdef CONFIG_IMA
>>> + struct ima_namespace *ima_ns;
>>> +#endif
>>> } __randomize_layout;
>>>
>>> struct ucounts {
>>> diff --git a/init/Kconfig b/init/Kconfig
>>> index 11f8a845f259..27890607e8cb 100644
>>> --- a/init/Kconfig
>>> +++ b/init/Kconfig
>>> @@ -1242,6 +1242,16 @@ config NET_NS
>>> Allow user space to create what appear to be multiple instances
>>> of the network stack.
>>>
>>> +config IMA_NS
>>> + bool "IMA namespace"
>>> + depends on USER_NS
>>> + depends on IMA
>>> + default y
>>> + help
>>> + Allow the creation of IMA namespaces for each user namespace.
>>> + Namespaced IMA enables having IMA features work separately
>>> + in each IMA namespace.
>>> +
>>> endif # NAMESPACES
>>>
>>> config CHECKPOINT_RESTORE
>>> diff --git a/kernel/user.c b/kernel/user.c
>>> index e2cf8c22b539..b5dc803a033d 100644
>>> --- a/kernel/user.c
>>> +++ b/kernel/user.c
>>> @@ -20,6 +20,10 @@
>>> #include <linux/user_namespace.h>
>>> #include <linux/proc_ns.h>
>>>
>>> +#ifdef CONFIG_IMA
>>> +extern struct ima_namespace init_ima_ns;
>>> +#endif
>>> +
>>> /*
>>> * userns count is 1 for root user, 1 for init_uts_ns,
>>> * and 1 for... ?
>>> @@ -55,7 +59,7 @@ struct user_namespace init_user_ns = {
>>> },
>>> },
>>> },
>>> - .ns.count = REFCOUNT_INIT(3),
>>> + .ns.count = REFCOUNT_INIT(4),
>>> .owner = GLOBAL_ROOT_UID,
>>> .group = GLOBAL_ROOT_GID,
>>> .ns.inum = PROC_USER_INIT_INO,
>>> @@ -67,6 +71,9 @@ 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
>>> + .ima_ns = &init_ima_ns,
>>> +#endif
>>> };
>>> EXPORT_SYMBOL_GPL(init_user_ns);
>>>
>>> diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
>>> index 6b2e3ca7ee99..c26885343b19 100644
>>> --- a/kernel/user_namespace.c
>>> +++ b/kernel/user_namespace.c
>>> @@ -20,6 +20,7 @@
>>> #include <linux/fs_struct.h>
>>> #include <linux/bsearch.h>
>>> #include <linux/sort.h>
>>> +#include <linux/ima.h>
>>>
>>> static struct kmem_cache *user_ns_cachep __read_mostly;
>>> static DEFINE_MUTEX(userns_state_mutex);
>>> @@ -141,8 +142,20 @@ int create_user_ns(struct cred *new)
>>> if (!setup_userns_sysctls(ns))
>>> goto fail_keyring;
>>>
>>> +#if CONFIG_IMA
>>> + ns->ima_ns = copy_ima_ns(parent_ns->ima_ns, ns);
>>> + if (IS_ERR(ns->ima_ns)) {
>>> + ret = PTR_ERR(ns->ima_ns);
>>> + goto fail_userns_sysctls;
>>> + }
>>> +#endif
>>> +
>>> set_cred_user_ns(new, ns);
>>> return 0;
>>> +#if CONFIG_IMA
>>> +fail_userns_sysctls:
>>> + retire_userns_sysctls(ns);
>>> +#endif
> If you rewrite copy_ima_ns() put_ima_ns() a little you can remove all
> the ifdefs in here and make this patch tiny.
>
> Make copy_ima_ns() return an int. Afaict, you can remove passing the
> parent ima_ns completely but if you have to pass through the
> parent_userns.
> Then you can initialize new_userns->ima_ns inside of copy_ima_ns() and
> the ifdef will only need to be visible inside copy_ima_ns() and not in
> create_user_ns(). Similar put_ima_ns() is only called in a single place
> namely kernel/user_namespace.c. Make it take a user_namespace argument
> and you can remove the ifdef in __put_user_ns() for put_ima_ns() too.
>
> So something -- COMPLETELY UNTESTED -- like the below should work:
Thanks. I did this now for v5.
Stefan