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=-15.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 9A655C5B57D for ; Wed, 3 Jul 2019 00:58:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 73C1A206A2 for ; Wed, 3 Jul 2019 00:58:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562115490; bh=ZncPmqJjQ5p8Nzi6KA3tSryklHFPA1+D6VokdeGHa28=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hExAohfocWUQtEsF40sioQb4EOxRR/beFdBwgp900uq2OsiC8LOPa2aFKwgActtdF 6yCB2thw24rBBeoQ5PuuTwYm5+bjqoCofBALVHVNA179gk15Gu4oq1kJ2sAJSqHSNW Fk0oeHijrsqqfdJVRdO4LE6fdy/+uQkZAiXtf64I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727448AbfGCA6J (ORCPT ); Tue, 2 Jul 2019 20:58:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:49336 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727089AbfGCA6F (ORCPT ); Tue, 2 Jul 2019 20:58:05 -0400 Received: from ebiggers-linuxstation.mtv.corp.google.com (unknown [104.132.1.77]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BC2DD20449; Tue, 2 Jul 2019 21:18:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562102286; bh=ZncPmqJjQ5p8Nzi6KA3tSryklHFPA1+D6VokdeGHa28=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SB5zOgdMv5+0+Y00OB/l2Jsui1egnX0iDRToH0chu73SQDnspeXPnukhhoEmUrnLn 1J+BRo9A3r/sqHCxARyy5JjA32jtlBzB0ijOU2DU7SGrhcMqqdeMDKnGYa4XxgYNle NM7aJFyBE6dbHGDyiqMab5d1sEPNEWHorvFmP4uM= From: Eric Biggers To: linux-crypto@vger.kernel.org, Herbert Xu Cc: chetjain@in.ibm.com, "David S . Miller" , linux-kernel@vger.kernel.org, Michal Suchanek , stable@vger.kernel.org, Steffen Klassert Subject: [PATCH] crypto: user - prevent operating on larval algorithms Date: Tue, 2 Jul 2019 14:17:00 -0700 Message-Id: <20190702211700.16526-1-ebiggers@kernel.org> X-Mailer: git-send-email 2.22.0.410.gd8fdbe21b5-goog In-Reply-To: <20190701153154.1569c2dc@kitsune.suse.cz> References: <20190701153154.1569c2dc@kitsune.suse.cz> MIME-Version: 1.0 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 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 --- crypto/crypto_user_base.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/crypto/crypto_user_base.c b/crypto/crypto_user_base.c index e48da3b75c71d4..a89fcc530092a8 100644 --- a/crypto/crypto_user_base.c +++ b/crypto/crypto_user_base.c @@ -56,6 +56,9 @@ struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact) 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; -- 2.22.0.410.gd8fdbe21b5-goog