diff mbox

[v6,5/8] ima: based on policy require signed firmware (sysfs fallback)

Message ID 1531505163-20227-6-git-send-email-zohar@linux.vnet.ibm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Mimi Zohar July 13, 2018, 6:06 p.m. UTC 
With an IMA policy requiring signed firmware, this patch prevents
the sysfs fallback method of loading firmware.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Matthew Garrett <mjg59@google.com>
---
 security/integrity/ima/ima_main.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

Comments

Kees Cook July 15, 2018, 2:27 a.m. UTC | #1 
On Fri, Jul 13, 2018 at 11:06 AM, Mimi Zohar <zohar@linux.vnet.ibm.com> wrote:
> With an IMA policy requiring signed firmware, this patch prevents
> the sysfs fallback method of loading firmware.
>
> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
> Cc: Luis R. Rodriguez <mcgrof@suse.com>
> Cc: Matthew Garrett <mjg59@google.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees
diff mbox

Patch

diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 71fecfef0939..e467664965e7 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -472,8 +472,10 @@  int ima_post_read_file(struct file *file, void *buf, loff_t size,
 
 	if (!file && read_id == READING_FIRMWARE) {
 		if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
-		    (ima_appraise & IMA_APPRAISE_ENFORCE))
+		    (ima_appraise & IMA_APPRAISE_ENFORCE)) {
+			pr_err("Prevent firmware loading_store.\n");
 			return -EACCES;	/* INTEGRITY_UNKNOWN */
+		}
 		return 0;
 	}
 
@@ -517,6 +519,12 @@  int ima_load_data(enum kernel_load_data_id id)
 			pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n");
 			return -EACCES;	/* INTEGRITY_UNKNOWN */
 		}
+		break;
+	case LOADING_FIRMWARE:
+		if (ima_appraise & IMA_APPRAISE_FIRMWARE) {
+			pr_err("Prevent firmware sysfs fallback loading.\n");
+			return -EACCES;	/* INTEGRITY_UNKNOWN */
+		}
 	default:
 		break;
 	}