Patch "iscsi-target: Fix rx_login_comp hang after login failure" has been added to the 3.10-stable tree

This is a note to let you know that I've just added the patch titled

iscsi-target: Fix rx_login_comp hang after login failure

to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
iscsi-target-fix-rx_login_comp-hang-after-login-failure.patch
and it can be found in the queue-3.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Nicholas Bellinger <[email protected]>
Date: Thu, 5 Nov 2015 14:11:59 -0800
Subject: iscsi-target: Fix rx_login_comp hang after login failure

From: Nicholas Bellinger <[email protected]>

commit ca82c2bded29b38d36140bfa1e76a7bbfcade390 upstream.

This patch addresses a case where iscsi_target_do_tx_login_io() fails sending the last login response PDU, after the RX/TX threads have already been started.

The case centers around iscsi_target_rx_thread() not invoking allow_signal(SIGINT) before the send_sig(SIGINT, ...) occurs from the failure path, resulting in RX thread hanging indefinately on iscsi_conn->rx_login_comp.

Note this bug is a regression introduced by:

commit e54198657b65625085834847ab6271087323ffea
Author: Nicholas Bellinger <[email protected]>
Date: Wed Jul 22 23:14:19 2015 -0700

iscsi-target: Fix iscsit_start_kthreads failure OOPs

To address this bug, complete ->rx_login_complete for good measure in the failure path, and immediately return from RX thread context if connection state did not actually reach full feature phase (TARG_CONN_STATE_LOGGED_IN).

---
 drivers/target/iscsi/iscsi_target.c      |   13 ++++++++++++-
 drivers/target/iscsi/iscsi_target_nego.c |    1 +
 2 files changed, 13 insertions(+), 1 deletion(-)

@@ -3960,6 +3960,17 @@ reject:
 	return iscsit_add_reject(conn, ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
 }
 
+static bool iscsi_target_check_conn_state(struct iscsi_conn *conn)
+{
+	bool ret;
+
+	spin_lock_bh(&conn->state_lock);
+	ret = (conn->conn_state != TARG_CONN_STATE_LOGGED_IN);
+	spin_unlock_bh(&conn->state_lock);
+
+	return ret;
+}
+
 int iscsi_target_rx_thread(void *arg)
 {
 	int ret, rc;

@@ -3977,7 +3988,7 @@ int iscsi_target_rx_thread(void *arg)
 	 * incoming iscsi/tcp socket I/O, and/or failing the connection.
 	 */
 	rc = wait_for_completion_interruptible(&conn->rx_login_comp);
-	if (rc < 0)
+	if (rc < 0 || iscsi_target_check_conn_state(conn))
 		return 0;
 
 	if (conn->conn_transport->transport_type == ISCSI_INFINIBAND) {

@@ -384,6 +384,7 @@ err:
 	if (login->login_complete) {
 		if (conn->rx_thread && conn->rx_thread_active) {
 			send_sig(SIGINT, conn->rx_thread, 1);
+			complete(&conn->rx_login_comp);
 			kthread_stop(conn->rx_thread);
 		}
 		if (conn->tx_thread && conn->tx_thread_active) {

Patches currently in stable-queue which might be from [email protected] are

queue-3.10/iscsi-target-fix-rx_login_comp-hang-after-login-failure.patch queue-3.10/iscsi-target-fix-potential-dead-lock-during-node-acl-delete.patch