From patchwork Mon Feb 22 12:13:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 386729 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35DDCC433DB for ; Mon, 22 Feb 2021 12:23:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EEDC364EEC for ; Mon, 22 Feb 2021 12:23:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230225AbhBVMVu (ORCPT ); Mon, 22 Feb 2021 07:21:50 -0500 Received: from mail.kernel.org ([198.145.29.99]:45452 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231152AbhBVMR5 (ORCPT ); Mon, 22 Feb 2021 07:17:57 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4CADD64E61; Mon, 22 Feb 2021 12:17:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1613996256; bh=YZ6GOVgbruHge1XWWbpHjjPHtO4T36kRZyv34rffeaM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=G/wze34X0qHHy1ea9Sb4dJgTVXlsVdFArZYQK80jo23pOlsuoZKaq6S/yVqU959eG It4VhAUzMNKP7yl+91tUQ6MPUmgn1mhudI5GCFfccWhoQkv+XTOdDyOx/4F6Z0NIL8 he+3a5CY8t5+ypseqdU3ll5I30Ka6BoHRNwcxB/k= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stefano Garzarella , "David S. Miller" Subject: [PATCH 4.19 33/50] vsock: fix locking in vsock_shutdown() Date: Mon, 22 Feb 2021 13:13:24 +0100 Message-Id: <20210222121026.072410085@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210222121019.925481519@linuxfoundation.org> References: <20210222121019.925481519@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Stefano Garzarella commit 1c5fae9c9a092574398a17facc31c533791ef232 upstream. In vsock_shutdown() we touched some socket fields without holding the socket lock, such as 'state' and 'sk_flags'. Also, after the introduction of multi-transport, we are accessing 'vsk->transport' in vsock_send_shutdown() without holding the lock and this call can be made while the connection is in progress, so the transport can change in the meantime. To avoid issues, we hold the socket lock when we enter in vsock_shutdown() and release it when we leave. Among the transports that implement the 'shutdown' callback, only hyperv_transport acquired the lock. Since the caller now holds it, we no longer take it. Fixes: d021c344051a ("VSOCK: Introduce VM Sockets") Signed-off-by: Stefano Garzarella Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/vmw_vsock/af_vsock.c | 8 +++++--- net/vmw_vsock/hyperv_transport.c | 4 ---- 2 files changed, 5 insertions(+), 7 deletions(-) --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -816,10 +816,12 @@ static int vsock_shutdown(struct socket */ sk = sock->sk; + + lock_sock(sk); if (sock->state == SS_UNCONNECTED) { err = -ENOTCONN; if (sk->sk_type == SOCK_STREAM) - return err; + goto out; } else { sock->state = SS_DISCONNECTING; err = 0; @@ -828,10 +830,8 @@ static int vsock_shutdown(struct socket /* Receive and send shutdowns are treated alike. */ mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN); if (mode) { - lock_sock(sk); sk->sk_shutdown |= mode; sk->sk_state_change(sk); - release_sock(sk); if (sk->sk_type == SOCK_STREAM) { sock_reset_flag(sk, SOCK_DONE); @@ -839,6 +839,8 @@ static int vsock_shutdown(struct socket } } +out: + release_sock(sk); return err; } --- a/net/vmw_vsock/hyperv_transport.c +++ b/net/vmw_vsock/hyperv_transport.c @@ -443,14 +443,10 @@ static void hvs_shutdown_lock_held(struc static int hvs_shutdown(struct vsock_sock *vsk, int mode) { - struct sock *sk = sk_vsock(vsk); - if (!(mode & SEND_SHUTDOWN)) return 0; - lock_sock(sk); hvs_shutdown_lock_held(vsk->trans, mode); - release_sock(sk); return 0; }