From patchwork Thu Apr 14 13:10:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 562341 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 C68A5C35280 for ; Thu, 14 Apr 2022 13:57:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344967AbiDNNwo (ORCPT ); Thu, 14 Apr 2022 09:52:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58426 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344792AbiDNNol (ORCPT ); Thu, 14 Apr 2022 09:44:41 -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 8393B38795; Thu, 14 Apr 2022 06:40:16 -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 038D961D7E; Thu, 14 Apr 2022 13:40:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0F4B0C385A1; Thu, 14 Apr 2022 13:40:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649943612; bh=StjqynMU0FVl6unB/pSncxQTzqqQXrq2twB8ET6DAyU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PamRrSvxHNSwNa73IsVyIEL5dLf03oxdAAIIEipSKmpyeHqTJh+HZXHrzlZ0+XLaK 7cKAfdPBYOlU6A6bGGmgUNrbk5ZYELb/b/KXOkOmaqaqZbIrIuN1kYodxP/hs6tg+m vpyQ51fucm6ouxOqETntJOBgKaGMGuJz3usk4cjQ= 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 5.4 216/475] bpf, sockmap: Fix double uncharge the mem of sk_msg Date: Thu, 14 Apr 2022 15:10:01 +0200 Message-Id: <20220414110901.169014846@linuxfoundation.org> X-Mailer: git-send-email 2.35.2 In-Reply-To: <20220414110855.141582785@linuxfoundation.org> References: <20220414110855.141582785@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 1584863bbdc1..bcc13368c836 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -296,10 +296,9 @@ 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);