Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756466Ab3CYBQn (ORCPT ); Sun, 24 Mar 2013 21:16:43 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:34148 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756370Ab3CYBQh (ORCPT ); Sun, 24 Mar 2013 21:16:37 -0400 Message-Id: <20130325010526.976899174@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 25 Mar 2013 01:05:51 +0000 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, Tomas Hozza , "K. Y. Srinivasan" , Greg Kroah-Hartman Subject: [ 027/104] tools: hv: Netlink source address validation allows DoS Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In-Reply-To: <20130325010524.240972766@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:f137:78a:b654:affb X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1644 Lines: 51 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tomas Hozza commit 95a69adab9acfc3981c504737a2b6578e4d846ef upstream. The source code without this patch caused hypervkvpd to exit when it processed a spoofed Netlink packet which has been sent from an untrusted local user. Now Netlink messages with a non-zero nl_pid source address are ignored and a warning is printed into the syslog. Signed-off-by: Tomas Hozza Acked-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- tools/hv/hv_kvp_daemon.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/tools/hv/hv_kvp_daemon.c +++ b/tools/hv/hv_kvp_daemon.c @@ -393,13 +393,19 @@ int main(void) len = recvfrom(fd, kvp_recv_buffer, sizeof(kvp_recv_buffer), 0, addr_p, &addr_l); - if (len < 0 || addr.nl_pid) { + if (len < 0) { syslog(LOG_ERR, "recvfrom failed; pid:%u error:%d %s", addr.nl_pid, errno, strerror(errno)); close(fd); return -1; } + if (addr.nl_pid) { + syslog(LOG_WARNING, "Received packet from untrusted pid:%u", + addr.nl_pid); + continue; + } + incoming_msg = (struct nlmsghdr *)kvp_recv_buffer; incoming_cn_msg = (struct cn_msg *)NLMSG_DATA(incoming_msg); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/