Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752473AbdFHNxY (ORCPT ); Thu, 8 Jun 2017 09:53:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56920 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751713AbdFHNtL (ORCPT ); Thu, 8 Jun 2017 09:49:11 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 2D34F30315C Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=dhowells@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 2D34F30315C Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 14/23] KEYS: user_defined: sanitize key payloads From: David Howells To: jmorris@namei.org Cc: dhowells@redhat.com, linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, linux-kernel@vger.kernel.org, Eric Biggers Date: Thu, 08 Jun 2017 14:49:04 +0100 Message-ID: <149692974429.11452.9095858900312530276.stgit@warthog.procyon.org.uk> In-Reply-To: <149692963884.11452.7673998701432248814.stgit@warthog.procyon.org.uk> References: <149692963884.11452.7673998701432248814.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Thu, 08 Jun 2017 13:49:06 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1752 Lines: 64 From: Eric Biggers Zero the payloads of user and logon keys before freeing them. This prevents sensitive key material from being kept around in the slab caches after a key is released. Signed-off-by: Eric Biggers Signed-off-by: David Howells --- security/keys/user_defined.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c index 26605134f17a..3d8c68eba516 100644 --- a/security/keys/user_defined.c +++ b/security/keys/user_defined.c @@ -86,10 +86,18 @@ EXPORT_SYMBOL_GPL(user_preparse); */ void user_free_preparse(struct key_preparsed_payload *prep) { - kfree(prep->payload.data[0]); + kzfree(prep->payload.data[0]); } EXPORT_SYMBOL_GPL(user_free_preparse); +static void user_free_payload_rcu(struct rcu_head *head) +{ + struct user_key_payload *payload; + + payload = container_of(head, struct user_key_payload, rcu); + kzfree(payload); +} + /* * update a user defined key * - the key's semaphore is write-locked @@ -112,7 +120,7 @@ int user_update(struct key *key, struct key_preparsed_payload *prep) prep->payload.data[0] = NULL; if (zap) - kfree_rcu(zap, rcu); + call_rcu(&zap->rcu, user_free_payload_rcu); return ret; } EXPORT_SYMBOL_GPL(user_update); @@ -130,7 +138,7 @@ void user_revoke(struct key *key) if (upayload) { rcu_assign_keypointer(key, NULL); - kfree_rcu(upayload, rcu); + call_rcu(&upayload->rcu, user_free_payload_rcu); } } @@ -143,7 +151,7 @@ void user_destroy(struct key *key) { struct user_key_payload *upayload = key->payload.data[0]; - kfree(upayload); + kzfree(upayload); } EXPORT_SYMBOL_GPL(user_destroy);