From patchwork Thu Jan 14 15:19:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= X-Patchwork-Id: 12019853 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32B34C4332E for ; Thu, 14 Jan 2021 15:21:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1ABCA23B06 for ; Thu, 14 Jan 2021 15:21:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729604AbhANPVA (ORCPT ); Thu, 14 Jan 2021 10:21:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47704 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729603AbhANPU7 (ORCPT ); Thu, 14 Jan 2021 10:20:59 -0500 Received: from smtp-1908.mail.infomaniak.ch (smtp-1908.mail.infomaniak.ch [IPv6:2001:1600:4:17::1908]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B12C1C061757 for ; Thu, 14 Jan 2021 07:19:55 -0800 (PST) Received: from smtp-3-0000.mail.infomaniak.ch (unknown [10.4.36.107]) by smtp-3-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4DGnyy5dGwzMq5Vl; Thu, 14 Jan 2021 16:19:06 +0100 (CET) Received: from localhost (unknown [23.97.221.149]) by smtp-3-0000.mail.infomaniak.ch (Postfix) with ESMTPA id 4DGnyy3VPxzlh8T3; Thu, 14 Jan 2021 16:19:06 +0100 (CET) From: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= To: David Howells , David Woodhouse , Jarkko Sakkinen Cc: =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= , "David S . Miller" , Herbert Xu , James Morris , =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= , Mimi Zohar , "Serge E . Hallyn" , keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, Ben Boeckel Subject: [PATCH v3 02/10] certs: Fix blacklisted hexadecimal hash string check Date: Thu, 14 Jan 2021 16:19:01 +0100 Message-Id: <20210114151909.2344974-3-mic@digikod.net> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210114151909.2344974-1-mic@digikod.net> References: <20210114151909.2344974-1-mic@digikod.net> MIME-Version: 1.0 Precedence: bulk List-ID: From: Mickaël Salaün When looking for a blacklisted hash, bin2hex() is used to transform a binary hash to an ascii (lowercase) hexadecimal string. This string is then search for in the description of the keys from the blacklist keyring. When adding a key to the blacklist keyring, blacklist_vet_description() checks the hash prefix and the hexadecimal string, but not that this string is lowercase. It is then valid to set hashes with uppercase hexadecimal, which will be silently ignored by the kernel. Add an additional check to blacklist_vet_description() to check that hexadecimal strings are in lowercase. Cc: David Woodhouse Signed-off-by: Mickaël Salaün Signed-off-by: David Howells Reviewed-by: Ben Boeckel --- Changes since v2: * Cherry-pick v1 patch from https://lore.kernel.org/lkml/2659836.1607940186@warthog.procyon.org.uk/ to rebase on v5.11-rc3. * Rearrange Cc order. --- certs/blacklist.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/certs/blacklist.c b/certs/blacklist.c index 2719fb2fbc1c..a888b934a1cd 100644 --- a/certs/blacklist.c +++ b/certs/blacklist.c @@ -37,7 +37,7 @@ static int blacklist_vet_description(const char *desc) found_colon: desc++; for (; *desc; desc++) { - if (!isxdigit(*desc)) + if (!isxdigit(*desc) || isupper(*desc)) return -EINVAL; n++; }