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 6B29FC433F5 for ; Tue, 1 Mar 2022 04:12:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232238AbiCAEMl (ORCPT ); Mon, 28 Feb 2022 23:12:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56026 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232237AbiCAEMj (ORCPT ); Mon, 28 Feb 2022 23:12:39 -0500 Received: from mail-io1-xd32.google.com (mail-io1-xd32.google.com [IPv6:2607:f8b0:4864:20::d32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DFF0359A65; Mon, 28 Feb 2022 20:11:58 -0800 (PST) Received: by mail-io1-xd32.google.com with SMTP id r8so3600059ioj.9; Mon, 28 Feb 2022 20:11:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:message-id:in-reply-to:references:subject :mime-version:content-transfer-encoding; bh=JizWy30NqngQ6w03lzthwcXJikA7CYicX/+9BAz4MlA=; b=STMAWXuvP/GtcJc48Qivw8j6/0RiafH9Cjxv2MwGwhGdxyGJlQatc95cWs8Igl3mhm WMSmy0N88p686/tnGCAcHJlfkjU0hIvlWamLA6VEhEI2SCaWP92TgAl7PNItcZsTsz+Z CH4+zUNwAQQsR7y/sxlGG+L7viPTsMfDWuTDYZvCY2ceTiOBZdC1J+n1A4lHkzM+xHUQ 8hNKPISZZdZW2ci/zaUfKgENIn0qauLN+kwcPFHkK9vy6TtD71jY/GJZkOuY2DKWQe+v n0uGqEg19xMdrijaJ25AqGebj+JnmMpA4zn64wUe6tD4HfJ82ZAxrCAQDCi4qrAL13TQ /2aQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:message-id:in-reply-to :references:subject:mime-version:content-transfer-encoding; bh=JizWy30NqngQ6w03lzthwcXJikA7CYicX/+9BAz4MlA=; b=EgT4xxTrrK492qFSPt2OVnsK04xQQ0kkSuRTmxYm2xnbiT7vOJ/CJB9qBJyfAbmCG3 KEIZzWBxAQ2Q+xgaazaVk+Z6aFmgrB5B/Ve8+/xKpx4rW42kXmLcpO6s8VjM/nb8Ob1d UfG9m/vF6noSA3DFY6gZMYfvW5g8eWB0JrcS3bpdENhU1V3G8fCNuFWJeoy8vqRuPgLz /7ax8IPdWuZC3Z8dlB6xFqGMCtL97Ll3/9QLIJgA9Bc/mSo/xkBMukZ/Pv/zjBgtDgRc nLCU2y9HOWxwS5PIVkT6QKHEoNK+EFxz0c5dEeLuI5VIyg1cGBGOfDuD2YNAYY2eX+t6 FdxQ== X-Gm-Message-State: AOAM530fnTQbRLbSVSaLzpbHPwSxHW9eSxLpnZ4LTxJ8tVq+nk4yOaHD hAZVIPJR5PaSNwj2Xu1V0IY= X-Google-Smtp-Source: ABdhPJx9RRWsgBlvoDlLpBPES6K7oeLPchGu0lHzyUOWf2CNhZWBgDtEtaij8OBEpV7m1UP9+krOpg== X-Received: by 2002:a05:6638:408:b0:313:f2bd:2d2 with SMTP id q8-20020a056638040800b00313f2bd02d2mr19883468jap.110.1646107918292; Mon, 28 Feb 2022 20:11:58 -0800 (PST) Received: from localhost ([99.197.200.79]) by smtp.gmail.com with ESMTPSA id y3-20020a920903000000b002be151ee1e6sm7181457ilg.30.2022.02.28.20.11.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Feb 2022 20:11:57 -0800 (PST) Date: Mon, 28 Feb 2022 20:11:50 -0800 From: John Fastabend To: Wang Yufen , john.fastabend@gmail.com, daniel@iogearbox.net, jakub@cloudflare.com, lmb@cloudflare.com, davem@davemloft.net, bpf@vger.kernel.org Cc: edumazet@google.com, yoshfuji@linux-ipv6.org, dsahern@kernel.org, kuba@kernel.org, ast@kernel.org, andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, kpsingh@kernel.org, netdev@vger.kernel.org, Wang Yufen Message-ID: <621d9d067de02_8c479208b9@john.notmuch> In-Reply-To: <20220225014929.942444-5-wangyufen@huawei.com> References: <20220225014929.942444-1-wangyufen@huawei.com> <20220225014929.942444-5-wangyufen@huawei.com> Subject: RE: [PATCH bpf-next 4/4] bpf, sockmap: Fix double uncharge the mem of sk_msg Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Wang Yufen wrote: > 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(), so we need to use sk_msg_free_nocharge while psock > is null. > > 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 | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c > index 1f0364e06619..03c037d2a055 100644 > --- a/net/ipv4/tcp_bpf.c > +++ b/net/ipv4/tcp_bpf.c > @@ -139,7 +139,7 @@ int tcp_bpf_sendmsg_redir(struct sock *sk, struct sk_msg *msg, > int ret; > > if (unlikely(!psock)) { > - sk_msg_free(sk, msg); > + sk_msg_free_nocharge(sk, msg); > return 0; > } > ret = ingress ? bpf_tcp_ingress(sk, psock, msg, bytes, flags) : Did you consider simply returning an error code here? 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 so I think it would be OK. Thanks, John