From patchwork Mon Aug 5 15:34:34 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ross Lagerwall X-Patchwork-Id: 11077211 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7D35C17E0 for ; Mon, 5 Aug 2019 15:36:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6CED61FFBD for ; Mon, 5 Aug 2019 15:36:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 617982884A; Mon, 5 Aug 2019 15:36:19 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 0C987205C0 for ; Mon, 5 Aug 2019 15:36:17 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1huf0U-0006uj-Uh; Mon, 05 Aug 2019 15:34:42 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1huf0U-0006ue-1B for xen-devel@lists.xenproject.org; Mon, 05 Aug 2019 15:34:42 +0000 X-Inumbo-ID: 8950a0ba-b796-11e9-8e5d-439c75b3fe30 Received: from esa3.hc3370-68.iphmx.com (unknown [216.71.145.155]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 8950a0ba-b796-11e9-8e5d-439c75b3fe30; Mon, 05 Aug 2019 15:34:39 +0000 (UTC) Authentication-Results: esa3.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none; spf=None smtp.pra=ross.lagerwall@citrix.com; spf=Pass smtp.mailfrom=ross.lagerwall@citrix.com; spf=None smtp.helo=postmaster@mail.citrix.com Received-SPF: None (esa3.hc3370-68.iphmx.com: no sender authenticity information available from domain of ross.lagerwall@citrix.com) identity=pra; client-ip=162.221.158.21; receiver=esa3.hc3370-68.iphmx.com; envelope-from="ross.lagerwall@citrix.com"; x-sender="ross.lagerwall@citrix.com"; x-conformance=sidf_compatible Received-SPF: Pass (esa3.hc3370-68.iphmx.com: domain of ross.lagerwall@citrix.com designates 162.221.158.21 as permitted sender) identity=mailfrom; client-ip=162.221.158.21; receiver=esa3.hc3370-68.iphmx.com; envelope-from="ross.lagerwall@citrix.com"; x-sender="ross.lagerwall@citrix.com"; x-conformance=sidf_compatible; x-record-type="v=spf1"; x-record-text="v=spf1 ip4:209.167.231.154 ip4:178.63.86.133 ip4:195.66.111.40/30 ip4:85.115.9.32/28 ip4:199.102.83.4 ip4:192.28.146.160 ip4:192.28.146.107 ip4:216.52.6.88 ip4:216.52.6.188 ip4:162.221.158.21 ip4:162.221.156.83 ~all" Received-SPF: None (esa3.hc3370-68.iphmx.com: no sender authenticity information available from domain of postmaster@mail.citrix.com) identity=helo; client-ip=162.221.158.21; receiver=esa3.hc3370-68.iphmx.com; envelope-from="ross.lagerwall@citrix.com"; x-sender="postmaster@mail.citrix.com"; x-conformance=sidf_compatible IronPort-SDR: MG3ZYEtER2WNBLk7cKJNOdkkcuRS1CfcERDgx+KKeOAZ18birOSwVaDoGmN6J5wHyqDQuNDlPo 2NMP/2mVtpyvDFsDetJxnpfrW62aypu0V88gQNBuncwFTW4ERaK4LcQ5Yim3TVEPVBLsctvPNu POCTx4WHjJdznFWGZlWrdXHDb9DPv4N3W4CvLmcgUI+QW2gyVvI6JEeLWS+x7lTTyC2SXUqAP9 nQ+DN+jzSXNcFnY+rTEx8Fdt+FA34PQ0zoc7N8tZJPVjhAojTm1my0ZBmZCZd918eQxIJ1kxWk hv8= X-SBRS: 2.7 X-MesageID: 3880647 X-Ironport-Server: esa3.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.64,350,1559534400"; d="scan'208";a="3880647" From: Ross Lagerwall To: Date: Mon, 5 Aug 2019 16:34:34 +0100 Message-ID: <20190805153434.12144-1-ross.lagerwall@citrix.com> X-Mailer: git-send-email 2.17.2 MIME-Version: 1.0 Subject: [Xen-devel] [PATCH] xen/netback: Reset nr_frags before freeing skb X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: xen-devel@lists.xenproject.org, Wei Liu , Paul Durrant , "David S. Miller" , Ross Lagerwall Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP At this point nr_frags has been incremented but the frag does not yet have a page assigned so freeing the skb results in a crash. Reset nr_frags before freeing the skb to prevent this. Signed-off-by: Ross Lagerwall --- drivers/net/xen-netback/netback.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 1d9940d4e8c7..c9262ffeefe4 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -925,6 +925,7 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue, skb_shinfo(skb)->nr_frags = MAX_SKB_FRAGS; nskb = xenvif_alloc_skb(0); if (unlikely(nskb == NULL)) { + skb_shinfo(skb)->nr_frags = 0; kfree_skb(skb); xenvif_tx_err(queue, &txreq, extra_count, idx); if (net_ratelimit()) @@ -940,6 +941,7 @@ static void xenvif_tx_build_gops(struct xenvif_queue *queue, if (xenvif_set_skb_gso(queue->vif, skb, gso)) { /* Failure in xenvif_set_skb_gso is fatal. */ + skb_shinfo(skb)->nr_frags = 0; kfree_skb(skb); kfree_skb(nskb); break;