Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756281Ab2KHSu5 (ORCPT ); Thu, 8 Nov 2012 13:50:57 -0500 Received: from ip-89-102-38-89.net.upcbroadband.cz ([89.102.38.89]:42916 "EHLO thozza-pc.brq.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752334Ab2KHSu4 (ORCPT ); Thu, 8 Nov 2012 13:50:56 -0500 X-Greylist: delayed 3589 seconds by postgrey-1.27 at vger.kernel.org; Thu, 08 Nov 2012 13:50:53 EST From: Tomas Hozza To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com, jasowang@redhat.com, kys@microsoft.com Cc: Tomas Hozza Subject: [PATCH] tools: hv: Netlink source address validation allows DoS Date: Wed, 7 Nov 2012 09:17:52 +0100 Message-Id: <1352276272-32126-1-git-send-email-thozza@redhat.com> X-Mailer: git-send-email 1.7.11.7 In-Reply-To: <20121106152911.GA1591@kroah.com> References: <20121106152911.GA1591@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1447 Lines: 43 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 --- tools/hv/hv_kvp_daemon.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c index 13c2a14..c1d9102 100755 --- a/tools/hv/hv_kvp_daemon.c +++ b/tools/hv/hv_kvp_daemon.c @@ -1486,13 +1486,19 @@ 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); hv_msg = (struct hv_kvp_msg *)incoming_cn_msg->data; -- 1.7.11.7 -- 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/