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=-6.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,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 09B2FC28CC0 for ; Thu, 30 May 2019 03:13:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D776E2452E for ; Thu, 30 May 2019 03:13:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559185986; bh=jRbH94i8EEbsYSk00/p/DOZAUYbkLLbNDdJOKu9f+1Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YB+iIb6ZmgvtBZ50L1c3Pd6U+TjhS+TTyjjdRGbxFnEhcEdNk23T29X18vEmQ4bd6 OCKnVz0jc9HHkdULl3JCcRPBix9Y9d4qwdJjfPOFx/g7PeI/NQkgfAF/BnBSgGb6UY nUAR61Y6aYXtPFKbhSnW7gWq03uXcyhge6ae6wzc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726376AbfE3DNG (ORCPT ); Wed, 29 May 2019 23:13:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:57286 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729327AbfE3DNE (ORCPT ); Wed, 29 May 2019 23:13:04 -0400 Received: from localhost (ip67-88-213-2.z213-88-67.customer.algx.net [67.88.213.2]) (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 2658C2452E; Thu, 30 May 2019 03:13:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559185983; bh=jRbH94i8EEbsYSk00/p/DOZAUYbkLLbNDdJOKu9f+1Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=an0VR1W3RnNzs24v/BkUGCwJT7g41lw2lqyeOD32zMa9QPKfXSjynwF/rMCaW1/6Z R9kBeG2jXwzAJ2PXG4CULRdA+ELAsF3gZMYB2OtAx+21uIwnUvm1RnYaEPA1ONYMnu KCM/WYt1gmJjRPE5Jph6juQSsyN978wYgpWpMNNM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Corentin Labbe , Kees Cook , Eric Biggers , Herbert Xu Subject: [PATCH 5.0 008/346] crypto: hash - fix incorrect HASH_MAX_DESCSIZE Date: Wed, 29 May 2019 20:01:21 -0700 Message-Id: <20190530030540.906315583@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190530030540.363386121@linuxfoundation.org> References: <20190530030540.363386121@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Biggers commit e1354400b25da645c4764ed6844d12f1582c3b66 upstream. The "hmac(sha3-224-generic)" algorithm has a descsize of 368 bytes, which is greater than HASH_MAX_DESCSIZE (360) which is only enough for sha3-224-generic. The check in shash_prepare_alg() doesn't catch this because the HMAC template doesn't set descsize on the algorithms, but rather sets it on each individual HMAC transform. This causes a stack buffer overflow when SHASH_DESC_ON_STACK() is used with hmac(sha3-224-generic). Fix it by increasing HASH_MAX_DESCSIZE to the real maximum. Also add a sanity check to hmac_init(). This was detected by the improved crypto self-tests in v5.2, by loading the tcrypt module with CONFIG_CRYPTO_MANAGER_EXTRA_TESTS=y enabled. I didn't notice this bug when I ran the self-tests by requesting the algorithms via AF_ALG (i.e., not using tcrypt), probably because the stack layout differs in the two cases and that made a difference here. KASAN report: BUG: KASAN: stack-out-of-bounds in memcpy include/linux/string.h:359 [inline] BUG: KASAN: stack-out-of-bounds in shash_default_import+0x52/0x80 crypto/shash.c:223 Write of size 360 at addr ffff8880651defc8 by task insmod/3689 CPU: 2 PID: 3689 Comm: insmod Tainted: G E 5.1.0-10741-g35c99ffa20edd #11 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x86/0xc5 lib/dump_stack.c:113 print_address_description+0x7f/0x260 mm/kasan/report.c:188 __kasan_report+0x144/0x187 mm/kasan/report.c:317 kasan_report+0x12/0x20 mm/kasan/common.c:614 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x137/0x190 mm/kasan/generic.c:191 memcpy+0x37/0x50 mm/kasan/common.c:125 memcpy include/linux/string.h:359 [inline] shash_default_import+0x52/0x80 crypto/shash.c:223 crypto_shash_import include/crypto/hash.h:880 [inline] hmac_import+0x184/0x240 crypto/hmac.c:102 hmac_init+0x96/0xc0 crypto/hmac.c:107 crypto_shash_init include/crypto/hash.h:902 [inline] shash_digest_unaligned+0x9f/0xf0 crypto/shash.c:194 crypto_shash_digest+0xe9/0x1b0 crypto/shash.c:211 generate_random_hash_testvec.constprop.11+0x1ec/0x5b0 crypto/testmgr.c:1331 test_hash_vs_generic_impl+0x3f7/0x5c0 crypto/testmgr.c:1420 __alg_test_hash+0x26d/0x340 crypto/testmgr.c:1502 alg_test_hash+0x22e/0x330 crypto/testmgr.c:1552 alg_test.part.7+0x132/0x610 crypto/testmgr.c:4931 alg_test+0x1f/0x40 crypto/testmgr.c:4952 Fixes: b68a7ec1e9a3 ("crypto: hash - Remove VLA usage") Reported-by: Corentin Labbe Cc: # v4.20+ Cc: Kees Cook Signed-off-by: Eric Biggers Reviewed-by: Kees Cook Tested-by: Corentin Labbe Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- crypto/hmac.c | 2 ++ include/crypto/hash.h | 8 +++++++- 2 files changed, 9 insertions(+), 1 deletion(-) --- a/crypto/hmac.c +++ b/crypto/hmac.c @@ -168,6 +168,8 @@ static int hmac_init_tfm(struct crypto_t parent->descsize = sizeof(struct shash_desc) + crypto_shash_descsize(hash); + if (WARN_ON(parent->descsize > HASH_MAX_DESCSIZE)) + return -EINVAL; ctx->hash = hash; return 0; --- a/include/crypto/hash.h +++ b/include/crypto/hash.h @@ -152,7 +152,13 @@ struct shash_desc { }; #define HASH_MAX_DIGESTSIZE 64 -#define HASH_MAX_DESCSIZE 360 + +/* + * Worst case is hmac(sha3-224-generic). Its context is a nested 'shash_desc' + * containing a 'struct sha3_state'. + */ +#define HASH_MAX_DESCSIZE (sizeof(struct shash_desc) + 360) + #define HASH_MAX_STATESIZE 512 #define SHASH_DESC_ON_STACK(shash, ctx) \