From mboxrd@z Thu Jan 1 00:00:00 1970 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=-11.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,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 0D7F0C606C1 for ; Mon, 8 Jul 2019 15:43:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D560320665 for ; Mon, 8 Jul 2019 15:43:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562600608; bh=XQyksg6BQprAUNPQBRwXdMzPOwjy+Jls0OH6AIq2J9M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YQ9RmvmcFtxHx7Y7SvhGGAIiaqbDMEjnpo0Q7KbFfVhtw7s3GMJMywt9iR5riX+GK DZO9SfIy/2GY/APZnrMLm6ooSIBgeX3d2jlDrwL4Nd+BeYSxYakMLrm7tDFnuYncwg VsDzRIDRtM0R9lnbYDjrBrFruBJPy7ubKM1GGCGk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391166AbfGHPn2 (ORCPT ); Mon, 8 Jul 2019 11:43:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:51634 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388344AbfGHPYX (ORCPT ); Mon, 8 Jul 2019 11:24:23 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5314221743; Mon, 8 Jul 2019 15:24:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562599462; bh=XQyksg6BQprAUNPQBRwXdMzPOwjy+Jls0OH6AIq2J9M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zbJ6+HI8mtVam6hkveGTsj0eg24KyQ7n7y5oVdwjpRjzP/VLrbodw2OHHJ9meT6IQ VjhideNPWKJRWpfkQus8NWmlURjdAQTx0jd69167ci9M3U0U7cTtqLBnaTt2wIurdX fOIyyYu/xcLFxNGRgVmpMmX4Ls+zClvsCvFdOj8U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michal Suchanek , Steffen Klassert , Eric Biggers , Herbert Xu Subject: [PATCH 4.14 24/56] crypto: user - prevent operating on larval algorithms Date: Mon, 8 Jul 2019 17:13:16 +0200 Message-Id: <20190708150521.596980733@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190708150514.376317156@linuxfoundation.org> References: <20190708150514.376317156@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Biggers commit 21d4120ec6f5b5992b01b96ac484701163917b63 upstream. Michal Suchanek reported [1] that running the pcrypt_aead01 test from LTP [2] in a loop and holding Ctrl-C causes a NULL dereference of alg->cra_users.next in crypto_remove_spawns(), via crypto_del_alg(). The test repeatedly uses CRYPTO_MSG_NEWALG and CRYPTO_MSG_DELALG. The crash occurs when the instance that CRYPTO_MSG_DELALG is trying to unregister isn't a real registered algorithm, but rather is a "test larval", which is a special "algorithm" added to the algorithms list while the real algorithm is still being tested. Larvals don't have initialized cra_users, so that causes the crash. Normally pcrypt_aead01 doesn't trigger this because CRYPTO_MSG_NEWALG waits for the algorithm to be tested; however, CRYPTO_MSG_NEWALG returns early when interrupted. Everything else in the "crypto user configuration" API has this same bug too, i.e. it inappropriately allows operating on larval algorithms (though it doesn't look like the other cases can cause a crash). Fix this by making crypto_alg_match() exclude larval algorithms. [1] https://lkml.kernel.org/r/20190625071624.27039-1-msuchanek@suse.de [2] https://github.com/linux-test-project/ltp/blob/20190517/testcases/kernel/crypto/pcrypt_aead01.c Reported-by: Michal Suchanek Fixes: a38f7907b926 ("crypto: Add userspace configuration API") Cc: # v3.2+ Cc: Steffen Klassert Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- crypto/crypto_user.c | 3 +++ 1 file changed, 3 insertions(+) --- a/crypto/crypto_user.c +++ b/crypto/crypto_user.c @@ -55,6 +55,9 @@ static struct crypto_alg *crypto_alg_mat list_for_each_entry(q, &crypto_alg_list, cra_list) { int match = 0; + if (crypto_is_larval(q)) + continue; + if ((q->cra_flags ^ p->cru_type) & p->cru_mask) continue;