From patchwork Mon Jan 11 13:01:41 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: 360949 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,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 9A389C43381 for ; Mon, 11 Jan 2021 13:56:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 717372231F for ; Mon, 11 Jan 2021 13:56:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728511AbhAKNz5 (ORCPT ); Mon, 11 Jan 2021 08:55:57 -0500 Received: from mail.kernel.org ([198.145.29.99]:54854 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730563AbhAKNHT (ORCPT ); Mon, 11 Jan 2021 08:07:19 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9EC0C22A84; Mon, 11 Jan 2021 13:06:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1610370399; bh=WekDsdLuuAVgarGa/JDddt4ocFNlWU4+ClsF8CDsbBk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oIwH08AHmMQ5sbib6ID2eSwAifaObW3nff3D5h0AEFsOusoJ6xAJi53tMl6BTWBgI eh0n5BN/l9TSPYhwlKdoEo3EpT5oG1DHr1+baM+oOhCI6wfqlqdXG9J8IMm2mAQf79 UkhALluAWJDlJTMKCIsSw8ScPFyCPivsllODKrbY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yunjian Wang , Willem de Bruijn , "Michael S. Tsirkin" , Jason Wang , Jakub Kicinski Subject: [PATCH 4.14 22/57] vhost_net: fix ubuf refcount incorrectly when sendmsg fails Date: Mon, 11 Jan 2021 14:01:41 +0100 Message-Id: <20210111130034.793721707@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111130033.715773309@linuxfoundation.org> References: <20210111130033.715773309@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Yunjian Wang [ Upstream commit 01e31bea7e622f1890c274f4aaaaf8bccd296aa5 ] Currently the vhost_zerocopy_callback() maybe be called to decrease the refcount when sendmsg fails in tun. The error handling in vhost handle_tx_zerocopy() will try to decrease the same refcount again. This is wrong. To fix this issue, we only call vhost_net_ubuf_put() when vq->heads[nvq->desc].len == VHOST_DMA_IN_PROGRESS. Fixes: bab632d69ee4 ("vhost: vhost TX zero-copy support") Signed-off-by: Yunjian Wang Acked-by: Willem de Bruijn Acked-by: Michael S. Tsirkin Acked-by: Jason Wang Link: https://lore.kernel.org/r/1609207308-20544-1-git-send-email-wangyunjian@huawei.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/vhost/net.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -466,6 +466,7 @@ static void handle_tx(struct vhost_net * size_t hdr_size; struct socket *sock; struct vhost_net_ubuf_ref *uninitialized_var(ubufs); + struct ubuf_info *ubuf; bool zcopy, zcopy_used; int sent_pkts = 0; @@ -532,9 +533,7 @@ static void handle_tx(struct vhost_net * /* use msg_control to pass vhost zerocopy ubuf info to skb */ if (zcopy_used) { - struct ubuf_info *ubuf; ubuf = nvq->ubuf_info + nvq->upend_idx; - vq->heads[nvq->upend_idx].id = cpu_to_vhost32(vq, head); vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS; ubuf->callback = vhost_zerocopy_callback; @@ -563,7 +562,8 @@ static void handle_tx(struct vhost_net * err = sock->ops->sendmsg(sock, &msg, len); if (unlikely(err < 0)) { if (zcopy_used) { - vhost_net_ubuf_put(ubufs); + if (vq->heads[ubuf->desc].len == VHOST_DMA_IN_PROGRESS) + vhost_net_ubuf_put(ubufs); nvq->upend_idx = ((unsigned)nvq->upend_idx - 1) % UIO_MAXIOV; }