[PATCH] [NET]: fix multicast list when cloning sockets

[Flavio Leitner <fleitner@redhat.com>]

The sock_copy() function uses memcpy() to clone the socket
including the struct ip_mc_socklist *mc_list pointer.

The ip_mc_drop_socket() function is called when socket is closed
to free these objects leaving the other sockets cloned from the
same master socket with invalid pointers.

This patch sets mc_list of cloned socket to NULL.

Signed-off-by: Flavio Leitner <fleitner@redhat.com>

diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index fbe7714..8ee0f54 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -506,6 +506,8 @@ struct sock *inet_csk_clone(struct sock *sk, const struct request_sock *req,
 		newicsk->icsk_backoff	  = 0;
 		newicsk->icsk_probes_out  = 0;
 
+		inet_sk(inet)->mc_list = NULL;
+
 		/* Deinitialize accept_queue to trap illegal accesses. */
 		memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
 
-- 
1.5.2.4

-- 
Flavio