[IPV6]: Fix OOPS when using IPV6_ADDRFORM

This causes sk->sk_prot to change, which makes the socket
release free the sock into the wrong SLAB cache.  Fix this
by introducing sk_prot_creator so that we always remember
where the sock came from.

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/net/sock.h b/include/net/sock.h
index cc4c9190b7fd..77f02f86346e 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -141,6 +141,7 @@ struct sock_common {
   *     @sk_callback_lock: used with the callbacks in the end of this struct
   *     @sk_error_queue: rarely used
   *     @sk_prot: protocol handlers inside a network family
+  *     @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt, IPV6_ADDRFORM for instance)
   *     @sk_err: last error
   *     @sk_err_soft: errors that don't cause failure but are the cause of a persistent failure not just 'timed out'
   *     @sk_ack_backlog: current listen backlog
@@ -218,6 +219,7 @@ struct sock {
         } sk_backlog;
         struct sk_buff_head     sk_error_queue;
         struct proto            *sk_prot;
+        struct proto            *sk_prot_creator;
         rwlock_t                sk_callback_lock;
         int                     sk_err,
                                 sk_err_soft;