[SCTP]: Fix assertion (!atomic_read(&sk->sk_rmem_alloc)) failed message

In current implementation, LKSCTP does receive buffer accounting for
data in sctp_receive_queue and pd_lobby. However, LKSCTP don't do
accounting for data in frag_list when data is fragmented. In addition,
LKSCTP doesn't do accounting for data in reasm and lobby queue in
structure sctp_ulpq.
When there are date in these queue, assertion failed message is printed
in inet_sock_destruct because sk_rmem_alloc of oldsk does not become 0
when socket is destroyed.

Signed-off-by: Tsutomu Fujii <t-fujii@nb.jp.nec.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 44 insertions, 4 deletions

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 536298c2eda..523e73ee354 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -5638,6 +5638,36 @@ void sctp_wait_for_close(struct sock *sk, long timeout)
         finish_wait(sk->sk_sleep, &wait);
 }
 
+static void sctp_sock_rfree_frag(struct sk_buff *skb)
+{
+        struct sk_buff *frag;
+
+        if (!skb->data_len)
+                goto done;
+
+        /* Don't forget the fragments. */
+        for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next)
+                sctp_sock_rfree_frag(frag);
+
+done:
+        sctp_sock_rfree(skb);
+}
+
+static void sctp_skb_set_owner_r_frag(struct sk_buff *skb, struct sock *sk)
+{
+        struct sk_buff *frag;
+
+        if (!skb->data_len)
+                goto done;
+
+        /* Don't forget the fragments. */
+        for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next)
+                sctp_skb_set_owner_r_frag(frag, sk);
+
+done:
+        sctp_skb_set_owner_r(skb, sk);
+}
+
 /* Populate the fields of the newsk from the oldsk and migrate the assoc
  * and its messages to the newsk.
  */
@@ -5692,10 +5722,10 @@ static void sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
         sctp_skb_for_each(skb, &oldsk->sk_receive_queue, tmp) {
                 event = sctp_skb2event(skb);
                 if (event->asoc == assoc) {
-                        sctp_sock_rfree(skb);
+                        sctp_sock_rfree_frag(skb);
                         __skb_unlink(skb, &oldsk->sk_receive_queue);
                         __skb_queue_tail(&newsk->sk_receive_queue, skb);
-                        sctp_skb_set_owner_r(skb, newsk);
+                        sctp_skb_set_owner_r_frag(skb, newsk);
                 }
         }
 
@@ -5723,10 +5753,10 @@ static void sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
                 sctp_skb_for_each(skb, &oldsp->pd_lobby, tmp) {
                         event = sctp_skb2event(skb);
                         if (event->asoc == assoc) {
-                                sctp_sock_rfree(skb);
+                                sctp_sock_rfree_frag(skb);
                                 __skb_unlink(skb, &oldsp->pd_lobby);
                                 __skb_queue_tail(queue, skb);
-                                sctp_skb_set_owner_r(skb, newsk);
+                                sctp_skb_set_owner_r_frag(skb, newsk);
                         }
                 }
 
@@ -5738,6 +5768,16 @@ static void sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
 
         }
 
+        sctp_skb_for_each(skb, &assoc->ulpq.reasm, tmp) {
+                sctp_sock_rfree_frag(skb);
+                sctp_skb_set_owner_r_frag(skb, newsk);
+        }
+
+        sctp_skb_for_each(skb, &assoc->ulpq.lobby, tmp) {
+                sctp_sock_rfree_frag(skb);
+                sctp_skb_set_owner_r_frag(skb, newsk);
+        }
+
         /* Set the type of socket to indicate that it is peeled off from the
          * original UDP-style socket or created with the accept() call on a
          * TCP-style socket..