[Oneiric CVE PATCH 1/1] Tools: hv: verify origin of netlink connector message

[Luis Henriques]

From: Olaf Hering <olaf at aepfle.de>

BugLink: https://launchpad.net/bugs/1096318

The SuSE security team suggested to use recvfrom instead of recv to be
certain that the connector message is originated from kernel.

CVE-2012-2669

Signed-off-by: Olaf Hering <olaf at aepfle.de>
Signed-off-by: Marcus Meissner <meissner at suse.de>
Signed-off-by: Sebastian Krahmer <krahmer at suse.de>
Signed-off-by: K. Y. Srinivasan <kys at microsoft.com>
Cc: stable <stable at vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
(backported from commit bcc2c9c3fff859e0eb019fe6fec26f9b8eba795c)

Signed-off-by: Luis Henriques <luis.henriques at canonical.com>

Conflicts:
	tools/hv/hv_kvp_daemon.c
---
 drivers/staging/hv/tools/hv_kvp_daemon.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/hv/tools/hv_kvp_daemon.c b/drivers/staging/hv/tools/hv_kvp_daemon.c
index 33f0f1c..1468a01 100644
--- a/drivers/staging/hv/tools/hv_kvp_daemon.c
+++ b/drivers/staging/hv/tools/hv_kvp_daemon.c
@@ -378,14 +378,18 @@ int main(void)
 	pfd.fd = fd;
 
 	while (1) {
+		struct sockaddr *addr_p = (struct sockaddr *) &addr;
+		socklen_t addr_l = sizeof(addr);
 		pfd.events = POLLIN;
 		pfd.revents = 0;
 		poll(&pfd, 1, -1);
 
-		len = recv(fd, kvp_recv_buffer, sizeof(kvp_recv_buffer), 0);
+		len = recvfrom(fd, kvp_recv_buffer, sizeof(kvp_recv_buffer), 0,
+				addr_p, &addr_l);
 
-		if (len < 0) {
-			syslog(LOG_ERR, "recv failed; error:%d", len);
+		if (len < 0 || addr.nl_pid) {
+			syslog(LOG_ERR, "recvfrom failed; pid:%u error:%d %s",
+					addr.nl_pid, errno, strerror(errno));
 			close(fd);
 			return -1;
 		}
-- 
1.8.0