Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv"

This reverts commit de058420767df21e2b6b0f3bb36d1616fb962032.

There is no actual tipc_node refcnt leak as stated in the above commit.
The refcnt is hold carefully for the case of an asynchronous decryption
(i.e. -EINPROGRESS/-EBUSY and skb = NULL is returned), so that the node
object cannot be freed in the meantime. The counter will be re-balanced
when the operation's callback arrives with the decrypted buffer if any.
In other cases, e.g. a synchronous crypto the counter will be decreased
immediately when it is done.

Now with that commit, a kernel panic will occur when there is no node
found (i.e. n = NULL) in the 'tipc_rcv()' or a premature release of the
node object.

This commit solves the issues by reverting the said commit, but keeping
one valid case that the 'skb_linearize()' is failed.

Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au>
Tested-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/tipc/node.c b/net/tipc/node.c
index 0312fb1..a4c2816 100644 (file)
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -2038,7 +2038,6 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b)
                n = tipc_node_find_by_id(net, ehdr->id);
        }
        tipc_crypto_rcv(net, (n) ? n->crypto_rx : NULL, &skb, b);
-       tipc_node_put(n);
        if (!skb)
                return;