From patchwork Wed Mar 30 08:50:09 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Ziyang Xuan (William)" X-Patchwork-Id: 12795583 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9FA16C433F5 for ; Wed, 30 Mar 2022 08:33:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244374AbiC3Ie4 (ORCPT ); Wed, 30 Mar 2022 04:34:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39996 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242851AbiC3Ie4 (ORCPT ); Wed, 30 Mar 2022 04:34:56 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C3BC7672; Wed, 30 Mar 2022 01:33:10 -0700 (PDT) Received: from canpemm500006.china.huawei.com (unknown [172.30.72.57]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4KT0773HJkz1GDBr; Wed, 30 Mar 2022 16:32:51 +0800 (CST) Received: from localhost.localdomain (10.175.104.82) by canpemm500006.china.huawei.com (7.192.105.130) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Wed, 30 Mar 2022 16:33:08 +0800 From: Ziyang Xuan To: , , , , , , CC: , , Subject: [PATCH net] net/tls: fix slab-out-of-bounds bug in decrypt_internal Date: Wed, 30 Mar 2022 16:50:09 +0800 Message-ID: <20220330085009.1011614-1-william.xuanziyang@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Originating-IP: [10.175.104.82] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To canpemm500006.china.huawei.com (7.192.105.130) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org The memory size of tls_ctx->rx.iv for AES128-CCM is 12 setting in tls_set_sw_offload(). The return value of crypto_aead_ivsize() for "ccm(aes)" is 16. So memcpy() require 16 bytes from 12 bytes memory space will trigger slab-out-of-bounds bug as following: ================================================================== BUG: KASAN: slab-out-of-bounds in decrypt_internal+0x385/0xc40 [tls] Read of size 16 at addr ffff888114e84e60 by task tls/10911 Call Trace: dump_stack_lvl+0x34/0x44 print_report.cold+0x5e/0x5db ? decrypt_internal+0x385/0xc40 [tls] kasan_report+0xab/0x120 ? decrypt_internal+0x385/0xc40 [tls] kasan_check_range+0xf9/0x1e0 memcpy+0x20/0x60 decrypt_internal+0x385/0xc40 [tls] ? tls_get_rec+0x2e0/0x2e0 [tls] ? process_rx_list+0x1a5/0x420 [tls] ? tls_setup_from_iter.constprop.0+0x2e0/0x2e0 [tls] decrypt_skb_update+0x9d/0x400 [tls] tls_sw_recvmsg+0x3c8/0xb50 [tls] Allocated by task 10911: kasan_save_stack+0x1e/0x40 __kasan_kmalloc+0x81/0xa0 tls_set_sw_offload+0x2eb/0xa20 [tls] tls_setsockopt+0x68c/0x700 [tls] __sys_setsockopt+0xfe/0x1b0 Reserve MAX_IV_SIZE memory space for iv to be compatible with all ciphers. And do iv and salt copy like done in tls_do_encryption(). Fixes: f295b3ae9f59 ("net/tls: Add support of AES128-CCM based ciphers") Signed-off-by: Ziyang Xuan --- net/tls/tls_sw.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 0024a692f0f8..6b858f995b23 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -1456,7 +1456,7 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb, aead_size = sizeof(*aead_req) + crypto_aead_reqsize(ctx->aead_recv); mem_size = aead_size + (nsg * sizeof(struct scatterlist)); mem_size = mem_size + prot->aad_size; - mem_size = mem_size + crypto_aead_ivsize(ctx->aead_recv); + mem_size = mem_size + MAX_IV_SIZE; /* Allocate a single block of memory which contains * aead_req || sgin[] || sgout[] || aad || iv. @@ -1493,12 +1493,8 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb, kfree(mem); return err; } - if (prot->version == TLS_1_3_VERSION || - prot->cipher_type == TLS_CIPHER_CHACHA20_POLY1305) - memcpy(iv + iv_offset, tls_ctx->rx.iv, - crypto_aead_ivsize(ctx->aead_recv)); - else - memcpy(iv + iv_offset, tls_ctx->rx.iv, prot->salt_size); + memcpy(iv + iv_offset, tls_ctx->rx.iv, + prot->iv_size + prot->salt_size); xor_iv_with_seq(prot, iv + iv_offset, tls_ctx->rx.rec_seq);