From patchwork Sat Sep 9 08:14:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liu Jian X-Patchwork-Id: 13378009 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 176CD1851 for ; Sat, 9 Sep 2023 08:11:23 +0000 (UTC) Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E37519BA for ; Sat, 9 Sep 2023 01:11:22 -0700 (PDT) Received: from canpemm500010.china.huawei.com (unknown [172.30.72.53]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4RjQZh5704zMl9k; Sat, 9 Sep 2023 16:07:56 +0800 (CST) Received: from huawei.com (10.175.101.6) by canpemm500010.china.huawei.com (7.192.105.118) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Sat, 9 Sep 2023 16:11:19 +0800 From: Liu Jian To: , , , , , , , , CC: Subject: [PATCH net v2] net/tls: do not free tls_rec on async operation in bpf_exec_tx_verdict() Date: Sat, 9 Sep 2023 16:14:34 +0800 Message-ID: <20230909081434.2324940-1-liujian56@huawei.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To canpemm500010.china.huawei.com (7.192.105.118) X-CFilter-Loop: Reflected X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED, RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org I got the below warning when do fuzzing test: BUG: KASAN: null-ptr-deref in scatterwalk_copychunks+0x320/0x470 Read of size 4 at addr 0000000000000008 by task kworker/u8:1/9 CPU: 0 PID: 9 Comm: kworker/u8:1 Tainted: G OE Hardware name: linux,dummy-virt (DT) Workqueue: pencrypt_parallel padata_parallel_worker Call trace: dump_backtrace+0x0/0x420 show_stack+0x34/0x44 dump_stack+0x1d0/0x248 __kasan_report+0x138/0x140 kasan_report+0x44/0x6c __asan_load4+0x94/0xd0 scatterwalk_copychunks+0x320/0x470 skcipher_next_slow+0x14c/0x290 skcipher_walk_next+0x2fc/0x480 skcipher_walk_first+0x9c/0x110 skcipher_walk_aead_common+0x380/0x440 skcipher_walk_aead_encrypt+0x54/0x70 ccm_encrypt+0x13c/0x4d0 crypto_aead_encrypt+0x7c/0xfc pcrypt_aead_enc+0x28/0x84 padata_parallel_worker+0xd0/0x2dc process_one_work+0x49c/0xbdc worker_thread+0x124/0x880 kthread+0x210/0x260 ret_from_fork+0x10/0x18 This is because the value of rec_seq of tls_crypto_info configured by the user program is too large, for example, 0xffffffffffffff. In addition, TLS is asynchronously accelerated. When tls_do_encryption() returns -EINPROGRESS and sk->sk_err is set to EBADMSG due to rec_seq overflow, skmsg is released before the asynchronous encryption process ends. As a result, the UAF problem occurs during the asynchronous processing of the encryption module. If the operation is asynchronous and the encryption module returns EINPROGRESS, do not free the record information. Fixes: 635d93981786 ("net/tls: free record only on encryption error") Signed-off-by: Liu Jian Reviewed-by: Sabrina Dubroca --- v1->v2: Retain the current EBADMSG error info and add error handling. net/tls/tls_sw.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 1ed4a611631f..d1fc295b83b5 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -817,7 +817,7 @@ static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk, psock = sk_psock_get(sk); if (!psock || !policy) { err = tls_push_record(sk, flags, record_type); - if (err && sk->sk_err == EBADMSG) { + if (err && err != -EINPROGRESS && sk->sk_err == EBADMSG) { *copied -= sk_msg_free(sk, msg); tls_free_open_rec(sk); err = -sk->sk_err; @@ -846,7 +846,7 @@ static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk, switch (psock->eval) { case __SK_PASS: err = tls_push_record(sk, flags, record_type); - if (err && sk->sk_err == EBADMSG) { + if (err && err != -EINPROGRESS && sk->sk_err == EBADMSG) { *copied -= sk_msg_free(sk, msg); tls_free_open_rec(sk); err = -sk->sk_err;