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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 23F38C433FE for ; Fri, 4 Mar 2022 07:54:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239023AbiCDHyw (ORCPT ); Fri, 4 Mar 2022 02:54:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56652 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239010AbiCDHyr (ORCPT ); Fri, 4 Mar 2022 02:54:47 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 285E8192E36; Thu, 3 Mar 2022 23:53:59 -0800 (PST) Received: from canpemm500010.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4K90Sl1Fzzzdb0N; Fri, 4 Mar 2022 15:52:39 +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; Fri, 4 Mar 2022 15:53:56 +0800 From: Wang Yufen To: , , , , , CC: , , , , , , , , , , , Wang Yufen Subject: [PATCH bpf-next v3 4/4] bpf, sockmap: Fix double uncharge the mem of sk_msg Date: Fri, 4 Mar 2022 16:11:45 +0800 Message-ID: <20220304081145.2037182-5-wangyufen@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220304081145.2037182-1-wangyufen@huawei.com> References: <20220304081145.2037182-1-wangyufen@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.104.82] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To canpemm500010.china.huawei.com (7.192.105.118) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org If tcp_bpf_sendmsg is running during a tear down operation, psock may be freed. tcp_bpf_sendmsg() tcp_bpf_send_verdict() sk_msg_return() tcp_bpf_sendmsg_redir() unlikely(!psock)) sk_msg_free() The mem of msg has been uncharged in tcp_bpf_send_verdict() by sk_msg_return(), and would be uncharged by sk_msg_free() again. When psock is null, we can simply returning an error code, this would then trigger the sk_msg_free_nocharge in the error path of __SK_REDIRECT and would have the side effect of throwing an error up to user space. This would be a slight change in behavior from user side but would look the same as an error if the redirect on the socket threw an error. This issue can cause the following info: WARNING: CPU: 0 PID: 2136 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 worker_thread+0x30/0x350 ? process_one_work+0x3c0/0x3c0 kthread+0xe6/0x110 ? kthread_complete_and_exit+0x20/0x20 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 | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c index 304800c60427..1cdcb4df0eb7 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -138,10 +138,9 @@ int tcp_bpf_sendmsg_redir(struct sock *sk, struct sk_msg *msg, struct sk_psock *psock = sk_psock_get(sk); int ret; - if (unlikely(!psock)) { - sk_msg_free(sk, msg); - return 0; - } + if (unlikely(!psock)) + return -EPIPE; + ret = ingress ? bpf_tcp_ingress(sk, psock, msg, bytes, flags) : tcp_bpf_push_locked(sk, msg, bytes, flags, false); sk_psock_put(sk, psock); -- 2.25.1