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authorParthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>2017-01-24 13:00:45 +0100
committerDavid S. Miller <davem@davemloft.net>2017-01-24 16:14:57 -0500
commitfc0adfc8fd18b61b6f7a3f28b429e134d6f3a008 (patch)
tree9080d3fca5d3fd7f654b16e290466c1ceb9b8a3f /net
parentd094c4d5f5c7e1b225e94227ca3f007be3adc4e8 (diff)
downloadlinux-fc0adfc8fd18b61b6f7a3f28b429e134d6f3a008.tar.bz2
tipc: fix connection refcount error
Until now, the generic server framework maintains the connection id's per subscriber in server's conn_idr. At tipc_close_conn, we remove the connection id from the server list, but the connection is valid until we call the refcount cleanup. Hence we have a window where the server allocates the same connection to an new subscriber leading to inconsistent reference count. We have another refcount warning we grab the refcount in tipc_conn_lookup() for connections with flag with CF_CONNECTED not set. This usually occurs at shutdown when the we stop the topology server and withdraw TIPC_CFG_SRV publication thereby triggering a withdraw message to subscribers. In this commit, we: 1. remove the connection from the server list at recount cleanup. 2. grab the refcount for a connection only if CF_CONNECTED is set. Tested-by: John Thompson <thompa.atl@gmail.com> Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/tipc/server.c19
1 files changed, 10 insertions, 9 deletions
diff --git a/net/tipc/server.c b/net/tipc/server.c
index 215849ce453d..2e803601aa99 100644
--- a/net/tipc/server.c
+++ b/net/tipc/server.c
@@ -91,7 +91,8 @@ static void tipc_sock_release(struct tipc_conn *con);
static void tipc_conn_kref_release(struct kref *kref)
{
struct tipc_conn *con = container_of(kref, struct tipc_conn, kref);
- struct sockaddr_tipc *saddr = con->server->saddr;
+ struct tipc_server *s = con->server;
+ struct sockaddr_tipc *saddr = s->saddr;
struct socket *sock = con->sock;
struct sock *sk;
@@ -106,6 +107,11 @@ static void tipc_conn_kref_release(struct kref *kref)
tipc_sock_release(con);
sock_release(sock);
con->sock = NULL;
+
+ spin_lock_bh(&s->idr_lock);
+ idr_remove(&s->conn_idr, con->conid);
+ s->idr_in_use--;
+ spin_unlock_bh(&s->idr_lock);
}
tipc_clean_outqueues(con);
@@ -128,8 +134,10 @@ static struct tipc_conn *tipc_conn_lookup(struct tipc_server *s, int conid)
spin_lock_bh(&s->idr_lock);
con = idr_find(&s->conn_idr, conid);
- if (con)
+ if (con && test_bit(CF_CONNECTED, &con->flags))
conn_get(con);
+ else
+ con = NULL;
spin_unlock_bh(&s->idr_lock);
return con;
}
@@ -198,15 +206,8 @@ static void tipc_sock_release(struct tipc_conn *con)
static void tipc_close_conn(struct tipc_conn *con)
{
- struct tipc_server *s = con->server;
-
if (test_and_clear_bit(CF_CONNECTED, &con->flags)) {
- spin_lock_bh(&s->idr_lock);
- idr_remove(&s->conn_idr, con->conid);
- s->idr_in_use--;
- spin_unlock_bh(&s->idr_lock);
-
/* We shouldn't flush pending works as we may be in the
* thread. In fact the races with pending rx/tx work structs
* are harmless for us here as we have already deleted this