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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,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 477B7C282C2 for ; Fri, 25 Jan 2019 10:46:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1613C218A2 for ; Fri, 25 Jan 2019 10:46:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="R6fRiCEu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727809AbfAYKqp (ORCPT ); Fri, 25 Jan 2019 05:46:45 -0500 Received: from mail-wr1-f67.google.com ([209.85.221.67]:42154 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725909AbfAYKqp (ORCPT ); Fri, 25 Jan 2019 05:46:45 -0500 Received: by mail-wr1-f67.google.com with SMTP id q18so9746985wrx.9; Fri, 25 Jan 2019 02:46:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=mQI/+sNPW3cWviJBz4RvXI4WSmKJyJbGpq6y4etWi2Y=; b=R6fRiCEuCyQwDdzgt9pkpz7iWPI1TjhhMLsrRoPbonYIHYVWgR6uCRYlvhoM+rbbRT M3q/elgkTOO/0brKEt3inLz4VoRCNWhZoErk1fa3VGwAoe+2DkAFFRfl3c1E3MjK/yEC LDo7U4brlqh5tErhSwJfU4AYq9Dh3379H5ZKNyoGL/j8WdfV7MCZzfU9iMK+TqymtLJQ z4CXIF8OC0absicNccaQdDDbMqM+kwcD5AMIwIi+LBODu1UbppGOpvZZkTm3H+37P39X mFKmAoaEnDPiK2zqxzAoaESS8e0F73AuZZ/yeBH/Sh4F+YX0MFDFHQAJ9HUpdu39972q nlqA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=mQI/+sNPW3cWviJBz4RvXI4WSmKJyJbGpq6y4etWi2Y=; b=rBpV/v51yXr9SYf/xdYgnsb8QD6DO+ym/enfDpeUoaumaBrqzjpDwB9fB8eqwhMSAr zO8NqI7AQBruEXFTyfyyRPz4g3NydYqfM05VhqkB9kVD+K+fzPVW/xncin4LMkwZJ33b 6A6cItpw9G0gSWcRFduzCcYy/j4608UWUKuQzEhcApIhycof5pkbZR8RRKl2sGPCGGor fkQOLOYjOpmfBbM3Vk8GaIichdIXmk2+uA7k4SpOzDFqaJ1CrCktr+r7xad91vCvDF4X fjYlQP8bRuZU9TfedfOtn2o6CtrCoyFmYkfiVE+TAf8smWciwn3hotgbZ1bRZkoOOy4m Wbsw== X-Gm-Message-State: AJcUukeYKzyI0UHVOga2/aDrImUJRryxGGXpLmt6eLTB7hOuKbgltZnB 7lp04RWFCAFD3ovLh5/0Jbw= X-Google-Smtp-Source: ALg8bN6LMdzwpe4WRzfoFT6cXa7L1JSSqHHjR0OtlNBhKSvY8PVLjps72JiBCwMBu+wMT9NR5PLaqA== X-Received: by 2002:a5d:6549:: with SMTP id z9mr10629625wrv.116.1548413203577; Fri, 25 Jan 2019 02:46:43 -0800 (PST) Received: from dvyukov-desk.muc.corp.google.com ([2a00:79e0:15:13:4c1a:d2d1:436c:979b]) by smtp.gmail.com with ESMTPSA id 143sm135792993wml.14.2019.01.25.02.46.42 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 25 Jan 2019 02:46:42 -0800 (PST) From: Dmitry Vyukov To: f6bvp@free.fr, davem@davemloft.net, linux-hams@vger.kernel.org, netdev@vger.kernel.org Cc: Dmitry Vyukov , syzbot+1a2c456a1ea08fa5b5f7@syzkaller.appspotmail.com, Ralf Baechle , linux-kernel@vger.kernel.org Subject: [PATCH] net/rose: fix NULL ax25_cb kernel panic Date: Fri, 25 Jan 2019 11:46:40 +0100 Message-Id: <20190125104640.253862-1-dvyukov@gmail.com> X-Mailer: git-send-email 2.20.1.495.gaa96b0ce6b-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Bernard Pidoux When an internally generated frame is handled by rose_xmit(), rose_route_frame() is called: if (!rose_route_frame(skb, NULL)) { dev_kfree_skb(skb); stats->tx_errors++; return NETDEV_TX_OK; } We have the same code sequence in Net/Rom where an internally generated frame is handled by nr_xmit() calling nr_route_frame(skb, NULL). However, in this function NULL argument is tested while it is not in rose_route_frame(). Then kernel panic occurs later on when calling ax25cmp() with a NULL ax25_cb argument as reported many times and recently with syzbot. We need to test if ax25 is NULL before using it. Testing: Built kernel with CONFIG_ROSE=y. Signed-off-by: Bernard Pidoux Acked-by: Dmitry Vyukov Reported-by: syzbot+1a2c456a1ea08fa5b5f7@syzkaller.appspotmail.com Cc: "David S. Miller" Cc: Ralf Baechle Cc: Bernard Pidoux Cc: linux-hams@vger.kernel.org Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- net/rose/rose_route.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/rose/rose_route.c b/net/rose/rose_route.c index 77e9f85a2c92..f2ff21d7df08 100644 --- a/net/rose/rose_route.c +++ b/net/rose/rose_route.c @@ -850,6 +850,7 @@ void rose_link_device_down(struct net_device *dev) /* * Route a frame to an appropriate AX.25 connection. + * A NULL ax25_cb indicates an internally generated frame. */ int rose_route_frame(struct sk_buff *skb, ax25_cb *ax25) { @@ -867,6 +868,10 @@ int rose_route_frame(struct sk_buff *skb, ax25_cb *ax25) if (skb->len < ROSE_MIN_LEN) return res; + + if (!ax25) + return rose_loopback_queue(skb, NULL); + frametype = skb->data[2]; lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF); if (frametype == ROSE_CALL_REQUEST && -- 2.20.1.495.gaa96b0ce6b-goog