From mboxrd@z Thu Jan 1 00:00:00 1970 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=unavailable 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 CDE92C433E0 for ; Mon, 11 Jan 2021 13:05:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8D137225AB for ; Mon, 11 Jan 2021 13:05:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730345AbhAKNFl (ORCPT ); Mon, 11 Jan 2021 08:05:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:52338 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730265AbhAKNFN (ORCPT ); Mon, 11 Jan 2021 08:05:13 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id D833422795; Mon, 11 Jan 2021 13:04:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1610370272; bh=rhR9TjcvCo4LY0to8vsWustufsGZtC9xR0beXfdgKVM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EXm9mYbhz4ToYz4r+vNBotqifquySV8Ad0G6Ofj67kYeLeZR2RM12aKZ7AwnWKOvO Gwy86oTVGv5wNNUk2LkRZeg2dB8u9gRsXDUnLXbyQSVXPHkO0yXS9hBDZcBefpnGPN NrhS/AyEnZL/qpd8C3IPxhlsQiAOXioAPa0JXMuw= 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 4.9 14/45] vhost_net: fix ubuf refcount incorrectly when sendmsg fails Date: Mon, 11 Jan 2021 14:00:52 +0100 Message-Id: <20210111130034.339702593@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111130033.676306636@linuxfoundation.org> References: <20210111130033.676306636@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 @@ -377,6 +377,7 @@ 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; @@ -444,9 +445,7 @@ 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; @@ -465,7 +464,8 @@ 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; }