ima: based on policy require signed firmware (sysfs fallback)

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>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Matthew Garrett <mjg59@google.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
This commit is contained in:
Mimi Zohar 2018-07-13 14:06:00 -04:00 committed by James Morris
parent 6e852651f2
commit fed2512a7c

View file

@ -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;
}