Thread (48 messages) 48 messages, 6 authors, 2022-01-19

Re: [PATCH v8 13/19] ima: Add functions for creation and freeing of an ima_namespace

From: Christian Brauner <brauner@kernel.org>
Date: 2022-01-14 11:43:37
Also in: linux-integrity, lkml

On Tue, Jan 04, 2022 at 12:04:10PM -0500, Stefan Berger wrote:
quoted hunk ↗ jump to hunk
From: Stefan Berger <stefanb@linux.ibm.com>

Implement create_ima_ns() to create and initialize an ima_namespace
and implement free_ima_ns() to free it.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
---
 include/linux/ima.h                      | 13 +++++
 security/integrity/ima/Makefile          |  1 +
 security/integrity/ima/ima.h             | 16 +++++++
 security/integrity/ima/ima_init_ima_ns.c |  2 +-
 security/integrity/ima/ima_ns.c          | 61 ++++++++++++++++++++++++
 5 files changed, 92 insertions(+), 1 deletion(-)
 create mode 100644 security/integrity/ima/ima_ns.c
diff --git a/include/linux/ima.h b/include/linux/ima.h
index e1d65162d1fb..06c88cb17b21 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -226,4 +226,17 @@ static inline bool ima_appraise_signature(enum kernel_read_file_id func)
 	return false;
 }
 #endif /* CONFIG_IMA_APPRAISE && CONFIG_INTEGRITY_TRUSTED_KEYRING */
+
+#ifdef CONFIG_IMA_NS
+
+void free_ima_ns(struct user_namespace *ns);
+
+#else
+
+static inline void free_ima_ns(struct user_namespace *user_ns)
+{
+}
+
+#endif /* CONFIG_IMA_NS */
+
 #endif /* _LINUX_IMA_H */
diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
index f8a5e5f3975d..b86a35fbed60 100644
--- a/security/integrity/ima/Makefile
+++ b/security/integrity/ima/Makefile
@@ -14,6 +14,7 @@ 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 f63c6f22b853..4255301e5b96 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -163,6 +163,7 @@ extern bool ima_canonical_fmt;
 int ima_init(void);
 int ima_fs_init(void);
 int ima_ns_init(void);
+int ima_init_namespace(struct ima_namespace *ns);
 int ima_add_template_entry(struct ima_namespace *ns,
 			   struct ima_template_entry *entry, int violation,
 			   const char *op, struct inode *inode,
@@ -503,4 +504,19 @@ static inline struct ima_namespace *get_current_ns(void)
 	return &init_ima_ns;
 }
 
+#ifdef CONFIG_IMA_NS
+
+struct ima_namespace *create_ima_ns(struct user_namespace *user_ns);
+
+#else
+
+static inline struct ima_namespace *
+create_ima_ns(struct user_namespace *user_ns)
Why are you introducing these functions in 13/19 when you're first using
it in the last patch of this series?
+{
+	WARN(1, "Cannot create an IMA namespace\n");
+	return ERR_PTR(-EFAULT);
+}
I think I pointed this out earlier or made illustrated it in my draft
patch earlier. This function should not return a ptr to an ima
namespace. That's just not necessary: the ima namespace _is stashed in
struct user namespace_:

static int create_ima_ns(struct uesr_namespace *user_ns)
{
	[...]

	/* Pairs with [...] */
	smp_store_release(&user_ns->ima_ns, ns);
	return 0;
}

and in the other case:

static inline create_ima_ns(struct user_namespace *user_ns)
{
	return -EINVAL;
}
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help