[PATCH v2] scsi: target: iscsi: cxgbit: fix csk leak

[PATCH v2] scsi: target: iscsi: cxgbit: fix csk leak

[Varun Prakash]

csk leak can happen if a new TCP connection gets established
after cxgbit_accept_np() returns, to fix this leak free
remaining csk in cxgbit_free_np().

v2: fix incorrect input to list_del_init().

Signed-off-by: Varun Prakash <varun@chelsio.com>
---
 drivers/target/iscsi/cxgbit/cxgbit_cm.c | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/drivers/target/iscsi/cxgbit/cxgbit_cm.c b/drivers/target/iscsi/cxgbit/cxgbit_cm.c
index 8de1601..71888b9 100644
--- a/drivers/target/iscsi/cxgbit/cxgbit_cm.c
+++ b/drivers/target/iscsi/cxgbit/cxgbit_cm.c
@@ -598,9 +598,12 @@ static void cxgbit_free_cdev_np(struct cxgbit_np *cnp)
 	mutex_unlock(&cdev_list_lock);
 }
 
+static void __cxgbit_free_conn(struct cxgbit_sock *csk);
+
 void cxgbit_free_np(struct iscsi_np *np)
 {
 	struct cxgbit_np *cnp = np->np_context;
+	struct cxgbit_sock *csk, *tmp;
 
 	cnp->com.state = CSK_STATE_DEAD;
 	if (cnp->com.cdev)
@@ -608,6 +611,13 @@ void cxgbit_free_np(struct iscsi_np *np)
 	else
 		cxgbit_free_all_np(cnp);
 
+	spin_lock_bh(&cnp->np_accept_lock);
+	list_for_each_entry_safe(csk, tmp, &cnp->np_accept_list, accept_node) {
+		list_del_init(&csk->accept_node);
+		__cxgbit_free_conn(csk);
+	}
+	spin_unlock_bh(&cnp->np_accept_lock);
+
 	np->np_context = NULL;
 	cxgbit_put_cnp(cnp);
 }
@@ -705,9 +715,9 @@ void cxgbit_abort_conn(struct cxgbit_sock *csk)
 			      csk->tid, 600, __func__);
 }
 
-void cxgbit_free_conn(struct iscsi_conn *conn)
+static void __cxgbit_free_conn(struct cxgbit_sock *csk)
 {
-	struct cxgbit_sock *csk = conn->context;
+	struct iscsi_conn *conn = csk->conn;
 	bool release = false;
 
 	pr_debug("%s: state %d\n",
@@ -716,7 +726,7 @@ void cxgbit_free_conn(struct iscsi_conn *conn)
 	spin_lock_bh(&csk->lock);
 	switch (csk->com.state) {
 	case CSK_STATE_ESTABLISHED:
-		if (conn->conn_state = TARG_CONN_STATE_IN_LOGOUT) {
+		if (conn && (conn->conn_state = TARG_CONN_STATE_IN_LOGOUT)) {
 			csk->com.state = CSK_STATE_CLOSING;
 			cxgbit_send_halfclose(csk);
 		} else {
@@ -741,6 +751,11 @@ void cxgbit_free_conn(struct iscsi_conn *conn)
 		cxgbit_put_csk(csk);
 }
 
+void cxgbit_free_conn(struct iscsi_conn *conn)
+{
+	__cxgbit_free_conn(conn->context);
+}
+
 static void cxgbit_set_emss(struct cxgbit_sock *csk, u16 opt)
 {
 	csk->emss = csk->com.cdev->lldi.mtus[TCPOPT_MSS_G(opt)] -
@@ -803,6 +818,7 @@ void _cxgbit_free_csk(struct kref *kref)
 	spin_unlock_bh(&cdev->cskq.lock);
 
 	cxgbit_free_skb(csk);
+	cxgbit_put_cnp(csk->cnp);
 	cxgbit_put_cdev(cdev);
 
 	kfree(csk);
@@ -1351,6 +1367,7 @@ cxgbit_pass_accept_req(struct cxgbit_device *cdev, struct sk_buff *skb)
 		goto rel_skb;
 	}
 
+	cxgbit_get_cnp(cnp);
 	cxgbit_get_cdev(cdev);
 
 	spin_lock(&cdev->cskq.lock);
-- 
2.0.2

Re: [PATCH v2] scsi: target: iscsi: cxgbit: fix csk leak

[Martin K. Petersen]

Varun,

> csk leak can happen if a new TCP connection gets established after
> cxgbit_accept_np() returns, to fix this leak free remaining csk in
> cxgbit_free_np().

Applied to 4.20/scsi-queue, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering