From patchwork Tue Aug 11 09:55:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Garzarella X-Patchwork-Id: 1343233 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=OsKAYPSO; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BQp9W1w1jz9sTS for ; Tue, 11 Aug 2020 19:55:27 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728519AbgHKJz0 (ORCPT ); Tue, 11 Aug 2020 05:55:26 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:45077 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728377AbgHKJzZ (ORCPT ); Tue, 11 Aug 2020 05:55:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1597139724; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=X5QR043eFCzv/Fon7C5jOnPIsUUCD+w4e/hQTP02T/8=; b=OsKAYPSO4V7I76EjkZ9n4l0fw1N4krRy3Tfbel73KrV6GzQpktAFHzQdwlOEBbyXxc+XJx Nc7gyzoMz9sc1qvvgb41H9Qhs4v6ZGspgK0jex2hvEPuXwOupOsQ7sHZdqKOMt8C/eJCUo 04g3f/UQVHtj7KCWk/hCxUjQydOOtOk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-224-wAptx2bLPwiDTCK21d8nqw-1; Tue, 11 Aug 2020 05:55:22 -0400 X-MC-Unique: wAptx2bLPwiDTCK21d8nqw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 796481940920; Tue, 11 Aug 2020 09:55:21 +0000 (UTC) Received: from steredhat.redhat.com (ovpn-113-182.ams2.redhat.com [10.36.113.182]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2C4035D9FC; Tue, 11 Aug 2020 09:55:18 +0000 (UTC) From: Stefano Garzarella To: davem@davemloft.net Cc: Jorgen Hansen , Stefano Garzarella , netdev@vger.kernel.org, Jakub Kicinski , Dexuan Cui , linux-kernel@vger.kernel.org, Stefan Hajnoczi Subject: [PATCH net 1/2] vsock: fix potential null pointer dereference in vsock_poll() Date: Tue, 11 Aug 2020 11:55:03 +0200 Message-Id: <20200811095504.25051-2-sgarzare@redhat.com> In-Reply-To: <20200811095504.25051-1-sgarzare@redhat.com> References: <20200811095504.25051-1-sgarzare@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org syzbot reported this issue where in the vsock_poll() we find the socket state at TCP_ESTABLISHED, but 'transport' is null: general protection fault, probably for non-canonical address 0xdffffc0000000012: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000090-0x0000000000000097] CPU: 0 PID: 8227 Comm: syz-executor.2 Not tainted 5.8.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:vsock_poll+0x75a/0x8e0 net/vmw_vsock/af_vsock.c:1038 Call Trace: sock_poll+0x159/0x460 net/socket.c:1266 vfs_poll include/linux/poll.h:90 [inline] do_pollfd fs/select.c:869 [inline] do_poll fs/select.c:917 [inline] do_sys_poll+0x607/0xd40 fs/select.c:1011 __do_sys_poll fs/select.c:1069 [inline] __se_sys_poll fs/select.c:1057 [inline] __x64_sys_poll+0x18c/0x440 fs/select.c:1057 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 This issue can happen if the TCP_ESTABLISHED state is set after we read the vsk->transport in the vsock_poll(). We could put barriers to synchronize, but this can only happen during connection setup, so we can simply check that 'transport' is valid. Fixes: c0cfa2d8a788 ("vsock: add multi-transports support") Reported-and-tested-by: syzbot+a61bac2fcc1a7c6623fe@syzkaller.appspotmail.com Signed-off-by: Stefano Garzarella --- net/vmw_vsock/af_vsock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index 27bbcfad9c17..9e93bc201cc0 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -1032,7 +1032,7 @@ static __poll_t vsock_poll(struct file *file, struct socket *sock, } /* Connected sockets that can produce data can be written. */ - if (sk->sk_state == TCP_ESTABLISHED) { + if (transport && sk->sk_state == TCP_ESTABLISHED) { if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { bool space_avail_now = false; int ret = transport->notify_poll_out( From patchwork Tue Aug 11 09:55:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Garzarella X-Patchwork-Id: 1343234 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=SSSp5xgA; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BQp9d2sW5z9sRN for ; Tue, 11 Aug 2020 19:55:33 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728535AbgHKJza (ORCPT ); Tue, 11 Aug 2020 05:55:30 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:42499 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728377AbgHKJz3 (ORCPT ); Tue, 11 Aug 2020 05:55:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1597139728; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0t6pyerkz2yQxFGUrBVr3335mJPptpvA69HZOPrEqE4=; b=SSSp5xgABeOzvYjcTmRh5mRWKboJwAKa3R9BdSYW/xm8vyZnwMxzCSC6pzKVcM0o7Vgeck VdveAp+DJ239ESjAMVqH8oFdytRDLlt6GrC8nQj0RpWJ7SpML4jd2xAkJxcfIGxuMpoqeI /hqmk6v7kMzjEK0h1ybtPD9KId7+T0U= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-13-GaghuQZsPpy8XUvNlyvc4w-1; Tue, 11 Aug 2020 05:55:26 -0400 X-MC-Unique: GaghuQZsPpy8XUvNlyvc4w-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 26077107ACCA; Tue, 11 Aug 2020 09:55:25 +0000 (UTC) Received: from steredhat.redhat.com (ovpn-113-182.ams2.redhat.com [10.36.113.182]) by smtp.corp.redhat.com (Postfix) with ESMTP id DE54D5D9FC; Tue, 11 Aug 2020 09:55:21 +0000 (UTC) From: Stefano Garzarella To: davem@davemloft.net Cc: Jorgen Hansen , Stefano Garzarella , netdev@vger.kernel.org, Jakub Kicinski , Dexuan Cui , linux-kernel@vger.kernel.org, Stefan Hajnoczi Subject: [PATCH net 2/2] vsock: small cleanup in vsock_poll() Date: Tue, 11 Aug 2020 11:55:04 +0200 Message-Id: <20200811095504.25051-3-sgarzare@redhat.com> In-Reply-To: <20200811095504.25051-1-sgarzare@redhat.com> References: <20200811095504.25051-1-sgarzare@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This patch combines nested if statements in a single one to reduce the indentation in vsock_poll(). It also combines an if nested in the else branch. The behavior isn't changed. Signed-off-by: Stefano Garzarella --- net/vmw_vsock/af_vsock.c | 27 ++++++++++++--------------- 1 file changed, 12 insertions(+), 15 deletions(-) diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index 9e93bc201cc0..2c80dc14fa60 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -1032,21 +1032,18 @@ static __poll_t vsock_poll(struct file *file, struct socket *sock, } /* Connected sockets that can produce data can be written. */ - if (transport && sk->sk_state == TCP_ESTABLISHED) { - if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { - bool space_avail_now = false; - int ret = transport->notify_poll_out( - vsk, 1, &space_avail_now); - if (ret < 0) { - mask |= EPOLLERR; - } else { - if (space_avail_now) - /* Remove EPOLLWRBAND since INET - * sockets are not setting it. - */ - mask |= EPOLLOUT | EPOLLWRNORM; - - } + if (transport && sk->sk_state == TCP_ESTABLISHED && + !(sk->sk_shutdown & SEND_SHUTDOWN)) { + bool space_avail_now = false; + int ret = transport->notify_poll_out(vsk, 1, + &space_avail_now); + if (ret < 0) { + mask |= EPOLLERR; + } else if (space_avail_now) { + /* Remove EPOLLWRBAND since INET + * sockets are not setting it. + */ + mask |= EPOLLOUT | EPOLLWRNORM; } }