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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 01E21C3A5A1 for ; Thu, 22 Aug 2019 17:26:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C0DEC2341B for ; Thu, 22 Aug 2019 17:26:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566494772; bh=Gj847P+qXm8y51Qcuet4CDKDoDTyJYgVLrmfPsIq1Ik=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hXcg7PLiiC7vb7gWSZ8GR4Gv6Olphdq2SFHJ+JmuI/9dAy47f6juTRBwjaetfgNQt my7iWpvMjJg08cMhLwij+cGdwdkMYwsoMD4e6PoqdSDwo90MyXOrMNAaFRp+JoK7qz 1MNPSYtwjDucenc9moke08dmwKK6zTiWd8Pf72jA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404654AbfHVR0L (ORCPT ); Thu, 22 Aug 2019 13:26:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:48216 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404336AbfHVRZK (ORCPT ); Thu, 22 Aug 2019 13:25:10 -0400 Received: from localhost (wsip-184-188-36-2.sd.sd.cox.net [184.188.36.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E39A12341B; Thu, 22 Aug 2019 17:25:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566494710; bh=Gj847P+qXm8y51Qcuet4CDKDoDTyJYgVLrmfPsIq1Ik=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DbNTuj2YGTJ1cLJ0a7ZWXZ9L6VkVzX9C6NNieh9r52/PhYSygCHss5aOVJh7awuJ1 MGl2QKy202rntimVr2ByetT5hnZ6fgzQA8m9qyBKQbwVoxkvQdK49nYhtiIaBITP9j XRslscbZSRMz3Ezurvgl0v6X2vWCtM9NqF1+tLMQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ross Lagerwall , "David S. Miller" Subject: [PATCH 4.14 65/71] xen/netback: Reset nr_frags before freeing skb Date: Thu, 22 Aug 2019 10:19:40 -0700 Message-Id: <20190822171730.557817012@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190822171726.131957995@linuxfoundation.org> References: <20190822171726.131957995@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ross Lagerwall [ Upstream commit 3a0233ddec554b886298de2428edb5c50a20e694 ] 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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/xen-netback/netback.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -927,6 +927,7 @@ static void xenvif_tx_build_gops(struct 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()) @@ -942,6 +943,7 @@ static void xenvif_tx_build_gops(struct 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;