From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:45798 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726599AbeKIHbS (ORCPT ); Fri, 9 Nov 2018 02:31:18 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sean Tranchetti , "David S. Miller" Subject: [PATCH 3.18 009/144] netlabel: check for IPV4MASK in addrinfo_get Date: Thu, 8 Nov 2018 13:49:40 -0800 Message-Id: <20181108215055.475987914@linuxfoundation.org> In-Reply-To: <20181108215054.826084593@linuxfoundation.org> References: <20181108215054.826084593@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sean Tranchetti [ Upstream commit f88b4c01b97e09535505cf3c327fdbce55c27f00 ] netlbl_unlabel_addrinfo_get() assumes that if it finds the NLBL_UNLABEL_A_IPV4ADDR attribute, it must also have the NLBL_UNLABEL_A_IPV4MASK attribute as well. However, this is not necessarily the case as the current checks in netlbl_unlabel_staticadd() and friends are not sufficent to enforce this. If passed a netlink message with NLBL_UNLABEL_A_IPV4ADDR, NLBL_UNLABEL_A_IPV6ADDR, and NLBL_UNLABEL_A_IPV6MASK attributes, these functions will all call netlbl_unlabel_addrinfo_get() which will then attempt dereference NULL when fetching the non-existent NLBL_UNLABEL_A_IPV4MASK attribute: Unable to handle kernel NULL pointer dereference at virtual address 0 Process unlab (pid: 31762, stack limit = 0xffffff80502d8000) Call trace: netlbl_unlabel_addrinfo_get+0x44/0xd8 netlbl_unlabel_staticremovedef+0x98/0xe0 genl_rcv_msg+0x354/0x388 netlink_rcv_skb+0xac/0x118 genl_rcv+0x34/0x48 netlink_unicast+0x158/0x1f0 netlink_sendmsg+0x32c/0x338 sock_sendmsg+0x44/0x60 ___sys_sendmsg+0x1d0/0x2a8 __sys_sendmsg+0x64/0xb4 SyS_sendmsg+0x34/0x4c el0_svc_naked+0x34/0x38 Code: 51001149 7100113f 540000a0 f9401508 (79400108) ---[ end trace f6438a488e737143 ]--- Kernel panic - not syncing: Fatal exception Signed-off-by: Sean Tranchetti Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/netlabel/netlabel_unlabeled.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/netlabel/netlabel_unlabeled.c +++ b/net/netlabel/netlabel_unlabeled.c @@ -787,7 +787,8 @@ static int netlbl_unlabel_addrinfo_get(s { u32 addr_len; - if (info->attrs[NLBL_UNLABEL_A_IPV4ADDR]) { + if (info->attrs[NLBL_UNLABEL_A_IPV4ADDR] && + info->attrs[NLBL_UNLABEL_A_IPV4MASK]) { addr_len = nla_len(info->attrs[NLBL_UNLABEL_A_IPV4ADDR]); if (addr_len != sizeof(struct in_addr) && addr_len != nla_len(info->attrs[NLBL_UNLABEL_A_IPV4MASK]))