[SCTP]: Fix a race between module load and protosw access

There is a race is SCTP between the loading of the module
and the access by the socket layer to the protocol functions.
In particular, a list of addresss that SCTP maintains is
not initialized prior to the registration with the protosw.
Thus it is possible for a user application to gain access
to SCTP functions before everything has been initialized.
The problem shows up as odd crashes during connection
initializtion when we try to access the SCTP address list.

The solution is to refactor how we do registration and
initialize the lists prior to registering with the protosw.
Care must be taken since the address list initialization
depends on some other pieces of SCTP initialization.  Also
the clean-up in case of failure now also needs to be refactored.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Acked-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 4 deletions

diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index 57df27f1958..57ed3e323d9 100644
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -380,15 +380,19 @@ static inline int sctp_sysctl_jiffies_ms(ctl_table *table, int __user *name, int
 
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 
-int sctp_v6_init(void);
-void sctp_v6_exit(void);
+void sctp_v6_pf_init(void);
+void sctp_v6_pf_exit(void);
+int sctp_v6_protosw_init(void);
+void sctp_v6_protosw_exit(void);
 int sctp_v6_add_protocol(void);
 void sctp_v6_del_protocol(void);
 
 #else /* #ifdef defined(CONFIG_IPV6) */
 
-static inline int sctp_v6_init(void) { return 0; }
-static inline void sctp_v6_exit(void) { return; }
+static inline void sctp_v6_pf_init(void) { return 0; }
+static inline void sctp_v6_pf_exit(void) { return; }
+static inline int sctp_v6_protosw_init(void) { return 0; }
+static inline void sctp_v6_protosw_exit(void) { return; }
 static inline int sctp_v6_add_protocol(void) { return 0; }
 static inline void sctp_v6_del_protocol(void) { return; }