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 AE6F3C3A5A1 for ; Thu, 22 Aug 2019 17:27:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 85C772341E for ; Thu, 22 Aug 2019 17:27:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566494873; bh=KOeSZJUB17lI2lE7sPcDKbmrILujAqWZ9WLxsvyzmW8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=y02MzZvTukG+Q6cDw4Gcj1tXINwGFaa/KqXUhBhZr+wh/WVjewMpx4+6Pl1bgcW/y Tgx1d1CNuZ3H1Pfo18XYRg2xgq4E0m796q9cayz5+IVf7u6PvYGzmajYkUqFqzdH3K ip5m2tnhbwhsKdfM1yWB67T6WA1GmzEbYyr6Wn2c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392055AbfHVR1w (ORCPT ); Thu, 22 Aug 2019 13:27:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:51616 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404686AbfHVR0R (ORCPT ); Thu, 22 Aug 2019 13:26:17 -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 CC29A206DD; Thu, 22 Aug 2019 17:26:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566494776; bh=KOeSZJUB17lI2lE7sPcDKbmrILujAqWZ9WLxsvyzmW8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lEHwyQvYk+NpIUrOr6z/UIn08Vkrusg6iUa6XGyaLGJVVNhIJbyhAvnKrPRu8s3XA n9lAyyloZRt9c0zyqzUxo1J9BS2HieAaqbuBqNEsAD514V/TnhAVAWMjZKlokuRx4K hfjpl/9tekzko4DghkDV3Rpv8DgwKO2NH39XbbOk= 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 4.19 82/85] xen/netback: Reset nr_frags before freeing skb Date: Thu, 22 Aug 2019 10:19:55 -0700 Message-Id: <20190822171734.620711532@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190822171731.012687054@linuxfoundation.org> References: <20190822171731.012687054@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 @@ -925,6 +925,7 @@ 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()) @@ -940,6 +941,7 @@ 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;