From patchwork Mon Feb 15 15:27:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 383243 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, 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 4FC18C433DB for ; Mon, 15 Feb 2021 15:36:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2A8BC64EB7 for ; Mon, 15 Feb 2021 15:36:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231185AbhBOPgI (ORCPT ); Mon, 15 Feb 2021 10:36:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:45570 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231231AbhBOPdH (ORCPT ); Mon, 15 Feb 2021 10:33:07 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id C2DFA64DC3; Mon, 15 Feb 2021 15:30:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1613403043; bh=7r2slUzHjXhtR3I88T96YfUhJ/cqHH7y2q3RscEMlgw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ToiBGUFvMytrg7tRWPZSCg4QcIdPwlM//SfzcT7tFEpiE6QkpdeeACmjx6qe5FsKF cHJjApv9hYTt1PCyN9BCNyV6FGaqwsjVBiPv6ozSWuY3B2b2EV0OUrnvtuobv38GTL aNb4kZBE2e9iExkLbzWgjMu97FlkeLOKSPDqyNQs= 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 5.4 57/60] vsock: fix locking in vsock_shutdown() Date: Mon, 15 Feb 2021 16:27:45 +0100 Message-Id: <20210215152717.203922591@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210215152715.401453874@linuxfoundation.org> References: <20210215152715.401453874@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 @@ -808,10 +808,12 @@ 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; @@ -820,10 +822,8 @@ 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); @@ -831,6 +831,8 @@ 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 @@ -464,14 +464,10 @@ 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; }