Tools: hv: verify origin of netlink connector message

commit bcc2c9c3fff859e0eb019fe6fec26f9b8eba795c upstream.

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@aepfle.de>
Signed-off-by: Marcus Meissner <meissner@suse.de>
Signed-off-by: Sebastian Krahmer <krahmer@suse.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
index 11224ed..323d4d9 100644 (file)
--- a/tools/hv/hv_kvp_daemon.c
+++ b/tools/hv/hv_kvp_daemon.c
@@ -384,14 +384,18 @@ 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;
                }