From patchwork Mon Feb 22 12:36:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 386127 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 0A040C433E6 for ; Mon, 22 Feb 2021 12:49:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AAD7164E4B for ; Mon, 22 Feb 2021 12:49:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231522AbhBVMt2 (ORCPT ); Mon, 22 Feb 2021 07:49:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:57154 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231446AbhBVMpX (ORCPT ); Mon, 22 Feb 2021 07:45:23 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0DA3564F4F; Mon, 22 Feb 2021 12:41:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1613997699; bh=j57vVxV/16lxams8bR5D0PRuyk9ypoZZaEsALguAg0w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KgNs23Riy37YxV0fMwCp9AuRCV/JcCw7lyl/8kwvMxUTq1YCGZyOCdT6d6kghKeRJ nuiMvnI1VH6TiBNdFyybmpkE29KZ1I1NaVF88KmVL7M3fUbNfNudPwkbiC/zmxg63J C1bIX6ozS+fpGlCLvmYn/II6CjQl7ZMOi/6LXI5I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , Norbert Slusarek , Stefano Garzarella , Jakub Kicinski Subject: [PATCH 4.9 31/49] net/vmw_vsock: improve locking in vsock_connect_timeout() Date: Mon, 22 Feb 2021 13:36:29 +0100 Message-Id: <20210222121027.241105561@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210222121022.546148341@linuxfoundation.org> References: <20210222121022.546148341@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Norbert Slusarek commit 3d0bc44d39bca615b72637e340317b7899b7f911 upstream. A possible locking issue in vsock_connect_timeout() was recognized by Eric Dumazet which might cause a null pointer dereference in vsock_transport_cancel_pkt(). This patch assures that vsock_transport_cancel_pkt() will be called within the lock, so a race condition won't occur which could result in vsk->transport to be set to NULL. Fixes: 380feae0def7 ("vsock: cancel packets when failing to connect") Reported-by: Eric Dumazet Signed-off-by: Norbert Slusarek Reviewed-by: Stefano Garzarella Link: https://lore.kernel.org/r/trinity-f8e0937a-cf0e-4d80-a76e-d9a958ba3ef1-1612535522360@3c-app-gmx-bap12 Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/vmw_vsock/af_vsock.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -1121,7 +1121,6 @@ static void vsock_connect_timeout(struct { struct sock *sk; struct vsock_sock *vsk; - int cancel = 0; vsk = container_of(work, struct vsock_sock, connect_work.work); sk = sk_vsock(vsk); @@ -1132,11 +1131,9 @@ static void vsock_connect_timeout(struct sk->sk_state = SS_UNCONNECTED; sk->sk_err = ETIMEDOUT; sk->sk_error_report(sk); - cancel = 1; + vsock_transport_cancel_pkt(vsk); } release_sock(sk); - if (cancel) - vsock_transport_cancel_pkt(vsk); sock_put(sk); }