[SCTP]: Add RCU synchronization around sctp_localaddr_list

sctp_localaddr_list is modified dynamically via NETDEV_UP
and NETDEV_DOWN events, but there is not synchronization
between writer (even handler) and readers.  As a result,
the readers can access an entry that has been freed and
crash the sytem.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Sridhar Samdurala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/sctp/bind_addr.c b/net/sctp/bind_addr.c
index fdb287a9e2e2..7fc369f9035d 100644
--- a/net/sctp/bind_addr.c
+++ b/net/sctp/bind_addr.c
@@ -163,8 +163,10 @@ int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new,
                 addr->a.v4.sin_port = htons(bp->port);
 
         addr->use_as_src = use_as_src;
+        addr->valid = 1;
 
         INIT_LIST_HEAD(&addr->list);
+        INIT_RCU_HEAD(&addr->rcu);
         list_add_tail(&addr->list, &bp->address_list);
         SCTP_DBG_OBJCNT_INC(addr);