From patchwork Tue Apr 5 07:25:15 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 557479 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 C070BC4707A for ; Tue, 5 Apr 2022 09:51:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243010AbiDEJio (ORCPT ); Tue, 5 Apr 2022 05:38:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243806AbiDEJJR (ORCPT ); Tue, 5 Apr 2022 05:09:17 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7BF8C7F; Tue, 5 Apr 2022 01:58:40 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 6AC4361594; Tue, 5 Apr 2022 08:58:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B777C385A8; Tue, 5 Apr 2022 08:58:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649149119; bh=vZCYosMR3xAeEcqaIxxhaQzuSAuF9vWSVdw/VukUcbY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Qgef9G6xTu7DjiJe3WKC7Tn9qII7H5VrISoBSLM/wJy3ny3LIfB3/AKxnI3X02Cz0 qtWP2yeI15DQqqpNFxmOjQ2yTrwpYVi4+wFLoE+sJXBHiaR7OtsZoiBT02x0M6qnq8 /RRAjIJ1fWIgVNpOUxrzPZP2rJ9/7aXDlZqFcvdI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Wang Yufen , Daniel Borkmann , John Fastabend , Sasha Levin Subject: [PATCH 5.16 0602/1017] bpf, sockmap: Fix double uncharge the mem of sk_msg Date: Tue, 5 Apr 2022 09:25:15 +0200 Message-Id: <20220405070412.147578366@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070354.155796697@linuxfoundation.org> References: <20220405070354.155796697@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Wang Yufen [ Upstream commit 2486ab434b2c2a14e9237296db00b1e1b7ae3273 ] 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 Signed-off-by: Daniel Borkmann Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20220304081145.2037182-5-wangyufen@huawei.com Signed-off-by: Sasha Levin --- 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);