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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 BB000C43334 for ; Mon, 3 Sep 2018 17:01:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7BB1820862 for ; Mon, 3 Sep 2018 17:01:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7BB1820862 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728811AbeICVWv (ORCPT ); Mon, 3 Sep 2018 17:22:51 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:38764 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727836AbeICVWv (ORCPT ); Mon, 3 Sep 2018 17:22:51 -0400 Received: from localhost (ip-213-127-74-90.ip.prioritytelecom.net [213.127.74.90]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 02B85CFC; Mon, 3 Sep 2018 17:01:50 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Florian Westphal , Eric Dumazet , "David S. Miller" , Sasha Levin Subject: [PATCH 4.4 20/80] atl1c: reserve min skb headroom Date: Mon, 3 Sep 2018 18:48:58 +0200 Message-Id: <20180903164934.966844901@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180903164934.171677301@linuxfoundation.org> References: <20180903164934.171677301@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Florian Westphal [ Upstream commit 6e56830776828d8ca9897fc4429eeab47c3bb432 ] Got crash report with following backtrace: BUG: unable to handle kernel paging request at ffff8801869daffe RIP: 0010:[] [] ip6_finish_output2+0x394/0x4c0 RSP: 0018:ffff880186c83a98 EFLAGS: 00010283 RAX: ffff8801869db00e ... [] ip6_finish_output+0x8c/0xf0 [] ip6_output+0x57/0x100 [] ip6_forward+0x4b9/0x840 [] ip6_rcv_finish+0x66/0xc0 [] ipv6_rcv+0x319/0x530 [] netif_receive_skb+0x1c/0x70 [] atl1c_clean+0x1ec/0x310 [atl1c] ... The bad access is in neigh_hh_output(), at skb->data - 16 (HH_DATA_MOD). atl1c driver provided skb with no headroom, so 14 bytes (ethernet header) got pulled, but then 16 are copied. Reserve NET_SKB_PAD bytes headroom, like netdev_alloc_skb(). Compile tested only; I lack hardware. Fixes: 7b7017642199 ("atl1c: Fix misuse of netdev_alloc_skb in refilling rx ring") Signed-off-by: Florian Westphal Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/atheros/atl1c/atl1c_main.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c +++ b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c @@ -1683,6 +1683,7 @@ static struct sk_buff *atl1c_alloc_skb(s skb = build_skb(page_address(page) + adapter->rx_page_offset, adapter->rx_frag_size); if (likely(skb)) { + skb_reserve(skb, NET_SKB_PAD); adapter->rx_page_offset += adapter->rx_frag_size; if (adapter->rx_page_offset >= PAGE_SIZE) adapter->rx_page = NULL;