Patchwork [3.5.y.z,extended,stable] Patch "tools: hv: Netlink source address validation allows DoS" has been added to staging queue

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Submitter Luis Henriques
Date March 22, 2013, 10:07 a.m.
Message ID <1363946830-7237-1-git-send-email-luis.henriques@canonical.com>
Download mbox | patch
Permalink /patch/229956/
State New
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Comments

Luis Henriques - March 22, 2013, 10:07 a.m.
This is a note to let you know that I have just added a patch titled

    tools: hv: Netlink source address validation allows DoS

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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From 313d067be9c2cad62869b46a8e138e0acef216a0 Mon Sep 17 00:00:00 2001
From: Tomas Hozza <thozza@redhat.com>
Date: Thu, 8 Nov 2012 10:53:29 +0100
Subject: [PATCH] tools: hv: Netlink source address validation allows DoS

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 <thozza@redhat.com>
Acked-by:  K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 tools/hv/hv_kvp_daemon.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

--
1.8.1.2

Patch

diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
index 2984ffb..60a8e29 100644
--- a/tools/hv/hv_kvp_daemon.c
+++ b/tools/hv/hv_kvp_daemon.c
@@ -727,13 +727,19 @@  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;