module: replace the existing LSM hook in init_module

Both the init_module and finit_module syscalls call either directly
or indirectly the security_kernel_read_file LSM hook.  This patch
replaces the direct call in init_module with a call to the new
security_kernel_load_data hook and makes the corresponding changes
in SELinux, LoadPin, and IMA.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>

1 files changed, 10 insertions, 13 deletions

diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index e467664965e7..ef349a761609 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -429,16 +429,6 @@ void ima_post_path_mknod(struct dentry *dentry)
  */
 int ima_read_file(struct file *file, enum kernel_read_file_id read_id)
 {
-	bool sig_enforce = is_module_sig_enforced();
-
-	if (!file && read_id == READING_MODULE) {
-		if (!sig_enforce && (ima_appraise & IMA_APPRAISE_MODULES) &&
-		    (ima_appraise & IMA_APPRAISE_ENFORCE)) {
-			pr_err("impossible to appraise a module without a file descriptor. sig_enforce kernel parameter might help\n");
-			return -EACCES;	/* INTEGRITY_UNKNOWN */
-		}
-		return 0;	/* We rely on module signature checking */
-	}
 	return 0;
 }
 
@@ -479,9 +469,6 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
 		return 0;
 	}
 
-	if (!file && read_id == READING_MODULE) /* MODULE_SIG_FORCE enabled */
-		return 0;
-
 	/* permit signed certs */
 	if (!file && read_id == READING_X509_CERTIFICATE)
 		return 0;
@@ -510,6 +497,8 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
  */
 int ima_load_data(enum kernel_load_data_id id)
 {
+	bool sig_enforce;
+
 	if ((ima_appraise & IMA_APPRAISE_ENFORCE) != IMA_APPRAISE_ENFORCE)
 		return 0;
 
@@ -525,6 +514,14 @@ int ima_load_data(enum kernel_load_data_id id)
 			pr_err("Prevent firmware sysfs fallback loading.\n");
 			return -EACCES;	/* INTEGRITY_UNKNOWN */
 		}
+		break;
+	case LOADING_MODULE:
+		sig_enforce = is_module_sig_enforced();
+
+		if (!sig_enforce && (ima_appraise & IMA_APPRAISE_MODULES)) {
+			pr_err("impossible to appraise a module without a file descriptor. sig_enforce kernel parameter might help\n");
+			return -EACCES;	/* INTEGRITY_UNKNOWN */
+		}
 	default:
 		break;
 	}