linux-kernel - [PATCH v8 04/17] integrity: Do not allow machine keyring updates following init

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: <20211124044124.998170-5-eric.snowberg@oracle.com>
Date:   Tue, 23 Nov 2021 23:41:11 -0500
From:   Eric Snowberg <eric.snowberg@...cle.com>
To:     keyrings@...r.kernel.org, linux-integrity@...r.kernel.org,
        zohar@...ux.ibm.com, dhowells@...hat.com, dwmw2@...radead.org,
        herbert@...dor.apana.org.au, davem@...emloft.net,
        jarkko@...nel.org, jmorris@...ei.org, serge@...lyn.com
Cc:     eric.snowberg@...cle.com, keescook@...omium.org,
        torvalds@...ux-foundation.org, weiyongjun1@...wei.com,
        nayna@...ux.ibm.com, ebiggers@...gle.com, ardb@...nel.org,
        nramas@...ux.microsoft.com, lszubowi@...hat.com, jason@...c4.com,
        linux-kernel@...r.kernel.org, linux-crypto@...r.kernel.org,
        linux-efi@...r.kernel.org, linux-security-module@...r.kernel.org,
        James.Bottomley@...senPartnership.com, pjones@...hat.com,
        konrad.wilk@...cle.com
Subject: [PATCH v8 04/17] integrity: Do not allow machine keyring updates following init

The machine keyring is setup during init.  No additional keys should be
allowed to be added afterwards.  Leave the permission as read only.

Signed-off-by: Eric Snowberg <eric.snowberg@...cle.com>
Reviewed-by: Mimi Zohar <zohar@...ux.ibm.com>
---
v2: Initial version
v4: Unmodified from v2
v5: Rename to machine keyring
v6: Add additional comment (suggested by Jarkko)
v7: Unmodified from v6
v8: Code unmodified from v7 added Mimi's Reviewed-by
---
 security/integrity/digsig.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index 8c315be8ad99..910fe29a5037 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -140,7 +140,13 @@ int __init integrity_init_keyring(const unsigned int id)
 		return -ENOMEM;
 
 	restriction->check = restrict_link_to_ima;
-	perm |= KEY_USR_WRITE;
+
+	/*
+	 * No additional keys shall be allowed to load into the machine
+	 * keyring following init
+	 */
+	if (id != INTEGRITY_KEYRING_MACHINE)
+		perm |= KEY_USR_WRITE;
 
 out:
 	return __integrity_init_keyring(id, perm, restriction);
-- 
2.18.4