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=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 F26DFC3A5A3 for ; Thu, 22 Aug 2019 17:45:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C1EA8205ED for ; Thu, 22 Aug 2019 17:45:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566495924; bh=/pDecIkCnISplXnioA/xEhrpBGiQSIbQdlks++4S2T4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Ge8nMXNA7ct+/sLinD3GQIMosWiftBrH7PG9rgUT4rwcR3m+aK0fuM1F3xpR1B4Qq o9Nx0HpQ/eVOihqQy7OW6IBj8HgGOsAMcDBT1Xpz7RIQ3+W4efYLZAeQVm7X7Oydd+ kVy6gvuNDqi0d4OiXebsDgPfS5J6VuEAJSNyJwHw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403834AbfHVRXH (ORCPT ); Thu, 22 Aug 2019 13:23:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:42136 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403795AbfHVRXD (ORCPT ); Thu, 22 Aug 2019 13:23:03 -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 A55002341D; Thu, 22 Aug 2019 17:23:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566494582; bh=/pDecIkCnISplXnioA/xEhrpBGiQSIbQdlks++4S2T4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vuVAuvmJl30r75W02PlR4Rm4GZ4CvfbfQsfqf7B+2AxkO2Gr4f+WlQZ0mvQPybT6H QcU1bwx46hIq7XcnTZIwvMFCrugMpybQobcep/irUCS6PSGgJ5AJgPFRDwGHOHKsEW ZyL+4eTf7iuUWYmrqkG4y1z41LlFYZo2dmH1g2ps= 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 4.4 75/78] xen/netback: Reset nr_frags before freeing skb Date: Thu, 22 Aug 2019 10:19:19 -0700 Message-Id: <20190822171834.203954783@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190822171832.012773482@linuxfoundation.org> References: <20190822171832.012773482@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 @@ -1421,6 +1421,7 @@ 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, idx); if (net_ratelimit()) @@ -1436,6 +1437,7 @@ 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;