tools: hv: daemon should subscribe only to CN_KVP_IDX group

Previously HyperV daemon set sockaddr_nl.nl_groups to CN_KVP_IDX.
Netlink documentation says: "nl_groups is a bit mask with every bit
representing a netlink group number". Since CN_KVP_IDX value is "9"
HyperV daemon was receiving Netlink messages also from group number
"1" which is used by CGroup Rules Engine Daemon. This caused the
daemon to segfault (at least on 2.6.32 kernel).

HyperV daemon should set nl_groups to zero and specify multicast
group CN_KVP_IDX only by using socket options.

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>

diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
index c800ea4c8bf92ee4e33158b636f14c2af509cb60..908a612ac9925c878e6e68846a99feeac25a5e4c 100644 (file)
--- a/tools/hv/hv_kvp_daemon.c
+++ b/tools/hv/hv_kvp_daemon.c
@@ -1443,7 +1443,7 @@ int main(void)
        addr.nl_family = AF_NETLINK;
        addr.nl_pad = 0;
        addr.nl_pid = 0;
-       addr.nl_groups = CN_KVP_IDX;
+       addr.nl_groups = 0;
 
 
        error = bind(fd, (struct sockaddr *)&addr, sizeof(addr));
@@ -1452,7 +1452,7 @@ int main(void)
                close(fd);
                exit(EXIT_FAILURE);
        }
-       sock_opt = addr.nl_groups;
+       sock_opt = CN_KVP_IDX;
        setsockopt(fd, 270, 1, &sock_opt, sizeof(sock_opt));
        /*
         * Register ourselves with the kernel.