linux-kernel - [PATCH v2 7/9] ima: based on policy require signed firmware (sysfs fallback)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1526568530-9144-8-git-send-email-zohar@linux.vnet.ibm.com>
Date:   Thu, 17 May 2018 10:48:48 -0400
From:   Mimi Zohar <zohar@...ux.vnet.ibm.com>
To:     linux-integrity@...r.kernel.org
Cc:     Mimi Zohar <zohar@...ux.vnet.ibm.com>,
        linux-security-module@...r.kernel.org,
        linux-kernel@...r.kernel.org, David Howells <dhowells@...hat.com>,
        "Luis R . Rodriguez" <mcgrof@...nel.org>,
        Eric Biederman <ebiederm@...ssion.com>,
        kexec@...ts.infradead.org, Andres Rodriguez <andresx7@...il.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        "Luis R . Rodriguez" <mcgrof@...e.com>,
        Matthew Garrett <mjg59@...gle.com>
Subject: [PATCH v2 7/9] 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@...ux.vnet.ibm.com>
Cc: Luis R. Rodriguez <mcgrof@...e.com>
Cc: David Howells <dhowells@...hat.com>
Cc: Matthew Garrett <mjg59@...gle.com>
---
 security/integrity/ima/ima_main.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 7e1a127f18fe..29d1a929af5c 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -451,7 +451,17 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id)
 		}
 		return 0;
 	}
+
+	if (read_id == READING_FIRMWARE_FALLBACK_SYSFS) {
+		if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
+		    (ima_appraise & IMA_APPRAISE_ENFORCE)) {
+			pr_err("Prevent firmware sysfs fallback loading.\n");
+			return -EACCES;
+		}
+		return 0;
+	}
 	return 0;
+
 }
 
 static int read_idmap[READING_MAX_ID] = {
-- 
2.7.5