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=-9.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,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 BE197C65C20 for ; Mon, 8 Oct 2018 15:26:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 789302150F for ; Mon, 8 Oct 2018 15:26:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="BSrvNxHd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 789302150F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.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 S1728284AbeJHWiu (ORCPT ); Mon, 8 Oct 2018 18:38:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:57508 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727747AbeJHWit (ORCPT ); Mon, 8 Oct 2018 18:38:49 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 966AC214DC; Mon, 8 Oct 2018 15:26:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539012394; bh=S/GkZS2+9OgY94dpp4slAN5jM+rJwrmhyUDG9RkHZ20=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BSrvNxHdBB4r5754NyBv8agWRSJhIpNWihBdDJPk9QNfedlniYb3eWm9gaMICywVD lWnrGefd9FFBKGXjRHoUUhxAYIBOiR8ZkzPdFkAoNeoGMWkrRr032xplF/HvsBnjd3 mQ652GNqH9T3DgOa7ps5UMIvcRpHslBzB18YRQYw= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Sven Eckelmann , Simon Wunderlich , Sasha Levin Subject: [PATCH AUTOSEL 4.14 03/32] batman-adv: Fix segfault when writing to throughput_override Date: Mon, 8 Oct 2018 11:26:00 -0400 Message-Id: <20181008152629.70812-3-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181008152629.70812-1-sashal@kernel.org> References: <20181008152629.70812-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sven Eckelmann [ Upstream commit b9fd14c20871e6189f635e49b32d7789e430b3c8 ] The per hardif sysfs file "batman_adv/throughput_override" prints the resulting change as info text when the users writes to this file. It uses the helper function batadv_info to add it at the same time to the kernel ring buffer and to the batman-adv debug log (when CONFIG_BATMAN_ADV_DEBUG is enabled). The function batadv_info requires as first parameter the batman-adv softif net_device. This parameter is then used to find the private buffer which contains the debug log for this batman-adv interface. But batadv_store_throughput_override used as first argument the slave net_device. This slave device doesn't have the batadv_priv private data which is access by batadv_info. Writing to this file with CONFIG_BATMAN_ADV_DEBUG enabled can either lead to a segfault or to memory corruption. Fixes: 0b5ecc6811bd ("batman-adv: add throughput override attribute to hard_ifaces") Signed-off-by: Sven Eckelmann Acked-by: Marek Lindner Signed-off-by: Simon Wunderlich Signed-off-by: Sasha Levin --- net/batman-adv/sysfs.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/batman-adv/sysfs.c b/net/batman-adv/sysfs.c index 0ae8b30e4eaa..ec412c5b8697 100644 --- a/net/batman-adv/sysfs.c +++ b/net/batman-adv/sysfs.c @@ -1078,8 +1078,9 @@ static ssize_t batadv_store_throughput_override(struct kobject *kobj, if (old_tp_override == tp_override) goto out; - batadv_info(net_dev, "%s: Changing from: %u.%u MBit to: %u.%u MBit\n", - "throughput_override", + batadv_info(hard_iface->soft_iface, + "%s: %s: Changing from: %u.%u MBit to: %u.%u MBit\n", + "throughput_override", net_dev->name, old_tp_override / 10, old_tp_override % 10, tp_override / 10, tp_override % 10); -- 2.17.1