From patchwork Mon Feb 21 10:31:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: wangyufen X-Patchwork-Id: 12753418 X-Patchwork-Delegate: bpf@iogearbox.net 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 335BEC433EF for ; Mon, 21 Feb 2022 10:51:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344755AbiBUKvn (ORCPT ); Mon, 21 Feb 2022 05:51:43 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:49444 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355798AbiBUKvR (ORCPT ); Mon, 21 Feb 2022 05:51:17 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 077D857B2F; Mon, 21 Feb 2022 02:13:18 -0800 (PST) Received: from canpemm500010.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4K2J0r0C46zbbc8; Mon, 21 Feb 2022 18:08:44 +0800 (CST) Received: from localhost.localdomain (10.175.104.82) 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 15.1.2308.21; Mon, 21 Feb 2022 18:13:11 +0800 From: Wang Yufen To: , , , CC: , , , , , , , , , , , , , Wang Yufen Subject: [PATCH net-next 2/4] bpf, sockmap: Fix memleak in tcp_bpf_sendmsg while sk msg is full Date: Mon, 21 Feb 2022 18:31:03 +0800 Message-ID: <20220221103105.4028557-3-wangyufen@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220221103105.4028557-1-wangyufen@huawei.com> References: <20220221103105.4028557-1-wangyufen@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.104.82] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To canpemm500010.china.huawei.com (7.192.105.118) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org If tcp_bpf_sendmsg() is running while sk msg is full, sk_msg_alloc() returns -ENOSPC, tcp_bpf_sendmsg() goto wait for memory. If partial memory has been alloced by sk_msg_alloc(), that is, msg_tx->sg.size is greater than osize after sk_msg_alloc(), memleak occurs. To fix we use sk_msg_trim() to release the allocated memory, then goto wait for memory. This issue can cause the following info: WARNING: CPU: 3 PID: 7950 at net/core/stream.c:208 sk_stream_kill_queues+0xd4/0x1a0 Call Trace: inet_csk_destroy_sock+0x55/0x110 __tcp_close+0x279/0x470 tcp_close+0x1f/0x60 inet_release+0x3f/0x80 __sock_release+0x3d/0xb0 sock_close+0x11/0x20 __fput+0x92/0x250 task_work_run+0x6a/0xa0 do_exit+0x33b/0xb60 do_group_exit+0x2f/0xa0 get_signal+0xb6/0x950 arch_do_signal_or_restart+0xac/0x2a0 exit_to_user_mode_prepare+0xa9/0x200 syscall_exit_to_user_mode+0x12/0x30 do_syscall_64+0x46/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae WARNING: CPU: 3 PID: 2094 at net/ipv4/af_inet.c:155 inet_sock_destruct+0x13c/0x260 Call Trace: __sk_destruct+0x24/0x1f0 sk_psock_destroy+0x19b/0x1c0 process_one_work+0x1b3/0x3c0 kthread+0xe6/0x110 ret_from_fork+0x22/0x30 Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: Wang Yufen --- net/ipv4/tcp_bpf.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c index 9b9b02052fd3..ac9f491cc139 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -421,8 +421,10 @@ static int tcp_bpf_sendmsg(struct sock *sk, struct msghdr *msg, size_t size) osize = msg_tx->sg.size; err = sk_msg_alloc(sk, msg_tx, msg_tx->sg.size + copy, msg_tx->sg.end - 1); if (err) { - if (err != -ENOSPC) + if (err != -ENOSPC) { + sk_msg_trim(sk, msg_tx, osize); goto wait_for_memory; + } enospc = true; copy = msg_tx->sg.size - osize; }