From patchwork Mon Jun 5 03:47:54 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Jason A. Donenfeld" X-Patchwork-Id: 9765403 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 661A660353 for ; Mon, 5 Jun 2017 03:49:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 572E127F8F for ; Mon, 5 Jun 2017 03:49:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4B57927F9F; Mon, 5 Jun 2017 03:49:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D011927FA6 for ; Mon, 5 Jun 2017 03:49:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751364AbdFEDtI (ORCPT ); Sun, 4 Jun 2017 23:49:08 -0400 Received: from frisell.zx2c4.com ([192.95.5.64]:36893 "EHLO frisell.zx2c4.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751325AbdFEDss (ORCPT ); Sun, 4 Jun 2017 23:48:48 -0400 Received: by frisell.zx2c4.com (ZX2C4 Mail Server) with ESMTP id f24fa526; Mon, 5 Jun 2017 03:48:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=zx2c4.com; h=from:to:cc :subject:date:message-id:in-reply-to:references; s=mail; bh=yBxz aLMhpsNF1cnuJ2o1aGuP/ao=; b=Ntx7TeKJGtdicOSnQoW/vleYaUphOXlnff5Z sj2KiJBU5t6/tMZ/Ks/VTSRmPRyadot5D4gENoTDq2lUkTveLG985uEP/tnBal2U d27U4pQqFPP0rDbZ1YnnKaI0sf7W41QAKkh8lfRpcqMcCFSZD/tszlI5Z0zBHvlN 9p0lpHXqoFDVPcCcdNVWQ0V4F05MfEAAF5GRJiFo0bGvl2JT/1H1tdV98z574iKB jiB1+Tlpcl3MHrP26lEHDxUHf2lO8Ua9amVy3ZGRImM7j06myCRYWOeLrmmMGLVZ gT7Z+T2LCoAYzDUZmE6m8g+mumB75G45uLHQvrPIqhOPJqNdtg== Received: by frisell.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id f8b3f4b6 (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256:NO); Mon, 5 Jun 2017 03:48:31 +0000 (UTC) From: "Jason A. Donenfeld" To: Theodore Ts'o , Linux Crypto Mailing List , LKML , kernel-hardening@lists.openwall.com, Greg Kroah-Hartman Cc: "Jason A. Donenfeld" , David Howells , Mimi Zohar , David Safford Subject: [PATCH RFC v2 5/8] security/keys: ensure RNG is seeded before use Date: Mon, 5 Jun 2017 05:47:54 +0200 Message-Id: <20170605034757.4803-6-Jason@zx2c4.com> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170605034757.4803-1-Jason@zx2c4.com> References: <20170605034757.4803-1-Jason@zx2c4.com> Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Otherwise, we might use bad random numbers which, particularly in the case of IV generation, could be quite bad. It makes sense to use the synchronous API here, because we're always in process context (as the code is littered with GFP_KERNEL and the like). Signed-off-by: Jason A. Donenfeld Cc: David Howells Cc: Mimi Zohar Cc: David Safford --- security/keys/encrypted-keys/encrypted.c | 8 +++++--- security/keys/key.c | 13 +++++++++---- 2 files changed, 14 insertions(+), 7 deletions(-) diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c index 0010955d7876..d51a28fc5cd5 100644 --- a/security/keys/encrypted-keys/encrypted.c +++ b/security/keys/encrypted-keys/encrypted.c @@ -777,10 +777,12 @@ static int encrypted_init(struct encrypted_key_payload *epayload, __ekey_init(epayload, format, master_desc, datalen); if (!hex_encoded_iv) { - get_random_bytes(epayload->iv, ivsize); + ret = get_random_bytes_wait(epayload->iv, ivsize); + if (unlikely(ret)) + return ret; - get_random_bytes(epayload->decrypted_data, - epayload->decrypted_datalen); + ret = get_random_bytes_wait(epayload->decrypted_data, + epayload->decrypted_datalen); } else ret = encrypted_key_decrypt(epayload, format, hex_encoded_iv); return ret; diff --git a/security/keys/key.c b/security/keys/key.c index 455c04d80bbb..1e0367475a4c 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -134,15 +134,18 @@ void key_user_put(struct key_user *user) * Allocate a serial number for a key. These are assigned randomly to avoid * security issues through covert channel problems. */ -static inline void key_alloc_serial(struct key *key) +static inline int key_alloc_serial(struct key *key) { struct rb_node *parent, **p; struct key *xkey; + int ret; /* propose a random serial number and look for a hole for it in the * serial number tree */ do { - get_random_bytes(&key->serial, sizeof(key->serial)); + ret = get_random_bytes_wait(&key->serial, sizeof(key->serial)); + if (unlikely(ret)) + return ret; key->serial >>= 1; /* negative numbers are not permitted */ } while (key->serial < 3); @@ -170,7 +173,7 @@ static inline void key_alloc_serial(struct key *key) rb_insert_color(&key->serial_node, &key_serial_tree); spin_unlock(&key_serial_lock); - return; + return 0; /* we found a key with the proposed serial number - walk the tree from * that point looking for the next unused serial number */ @@ -314,7 +317,9 @@ struct key *key_alloc(struct key_type *type, const char *desc, /* publish the key by giving it a serial number */ atomic_inc(&user->nkeys); - key_alloc_serial(key); + ret = key_alloc_serial(key); + if (ret < 0) + goto security_error; error: return key;