From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-2243538-1518720549-2-1073614036428625502 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.001, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES unknown, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1518720548; b=gNh9iWtpS2dIL25Yfl00EArzw9IbmOizF60kmYsdzY5HGfO 8bYz9B2Cs4Ak1yT1CoFFor0aIWzSEN8PZPM9KW4wuiL89LVwcXnAKJB+CcVPz5C3 WvK87hxaUSqFzedL8aJgIA0Xt9hTvCOjFDjoLMcVvUEOtZxxv2TyLkD++UAG71du NhaQfULf/Uriy3vGixryh4zlKEZBw1cnho8Kq//cLZ3Tj4ZYQw830WcrO+pp/ZyM YEtp1ZqJTwNHPoUkeAEMDcT6Rlzq4c21uZgq89YfRu2r9MIPkQ8HqSjtV0/RCE0U CNMp/vdwlVAzx2GPoe3kMCNP93/wujkJgBu0NEQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type:sender :list-id; s=arctest; t=1518720548; bh=vgb8dxUM2fkvgh59sBzUT5xuI/ YQ8kOI2SDMrIdbg7c=; b=tQiuYbdw/xlpi6l0wlLZ7G+FHn7hTFT0zuV7zZEuau zqfEcJQoanXd5SzUMJx4bFUp0BXsZU8do2pJsPFN62KEtGkBxWi7c5qO94Vc2boR SvSlCoX40ww6huMo5osmf3zaXA++oReTs3DcKl94JG5MZQVENBPf99d88ljJCAhD vDukT1XWOhU14e51UbycybL6sCOjTddaG1x487zezVJYXDVccAsyMBcvHVArXD2K 2P6brH1c7RMk/3/DglWStx8xuyM1UmXu8HevVL7n4X5G/pfibFGW14GHxtDA6B4B rJzZ9ptyBLr12Stiaip/vsBYVR6UGAvE7WcAF2aVFUiw== ARC-Authentication-Results: i=1; mx5.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Authentication-Results: mx5.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162229AbeBOPV6 (ORCPT ); Thu, 15 Feb 2018 10:21:58 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:49298 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1162138AbeBOPV4 (ORCPT ); Thu, 15 Feb 2018 10:21:56 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mimi Zohar , Eric Biggers , David Howells , James Morris , Jin Qian Subject: [PATCH 4.4 034/108] KEYS: encrypted: fix buffer overread in valid_master_desc() Date: Thu, 15 Feb 2018 16:16:31 +0100 Message-Id: <20180215151227.176503087@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180215151222.267507937@linuxfoundation.org> References: <20180215151222.267507937@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Biggers commit 794b4bc292f5d31739d89c0202c54e7dc9bc3add upstream. With the 'encrypted' key type it was possible for userspace to provide a data blob ending with a master key description shorter than expected, e.g. 'keyctl add encrypted desc "new x" @s'. When validating such a master key description, validate_master_desc() could read beyond the end of the buffer. Fix this by using strncmp() instead of memcmp(). [Also clean up the code to deduplicate some logic.] Cc: Mimi Zohar Signed-off-by: Eric Biggers Signed-off-by: David Howells Signed-off-by: James Morris Signed-off-by: Jin Qian Signed-off-by: Greg Kroah-Hartman --- security/keys/encrypted-keys/encrypted.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) --- a/security/keys/encrypted-keys/encrypted.c +++ b/security/keys/encrypted-keys/encrypted.c @@ -141,23 +141,22 @@ static int valid_ecryptfs_desc(const cha */ static int valid_master_desc(const char *new_desc, const char *orig_desc) { - if (!memcmp(new_desc, KEY_TRUSTED_PREFIX, KEY_TRUSTED_PREFIX_LEN)) { - if (strlen(new_desc) == KEY_TRUSTED_PREFIX_LEN) - goto out; - if (orig_desc) - if (memcmp(new_desc, orig_desc, KEY_TRUSTED_PREFIX_LEN)) - goto out; - } else if (!memcmp(new_desc, KEY_USER_PREFIX, KEY_USER_PREFIX_LEN)) { - if (strlen(new_desc) == KEY_USER_PREFIX_LEN) - goto out; - if (orig_desc) - if (memcmp(new_desc, orig_desc, KEY_USER_PREFIX_LEN)) - goto out; - } else - goto out; + int prefix_len; + + if (!strncmp(new_desc, KEY_TRUSTED_PREFIX, KEY_TRUSTED_PREFIX_LEN)) + prefix_len = KEY_TRUSTED_PREFIX_LEN; + else if (!strncmp(new_desc, KEY_USER_PREFIX, KEY_USER_PREFIX_LEN)) + prefix_len = KEY_USER_PREFIX_LEN; + else + return -EINVAL; + + if (!new_desc[prefix_len]) + return -EINVAL; + + if (orig_desc && strncmp(new_desc, orig_desc, prefix_len)) + return -EINVAL; + return 0; -out: - return -EINVAL; } /*