From db6077fd0b7dd41dc6ff18329cec979379071f87 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Wed, 11 Dec 2013 15:45:32 -0800 Subject: [PATCH] iscsi-target: Fix incorrect np->np_thread NULL assignment When shutting down a target there is a race condition between iscsit_del_np() and __iscsi_target_login_thread(). The latter sets the thread pointer to NULL, and the former tries to issue kthread_stop() on that pointer without any synchronization. This patch moves the np->np_thread NULL assignment into iscsit_del_np(), after kthread_stop() has completed. It also removes the signal_pending() + np_state check, and only exits when kthread_should_stop() is true. Reported-by: Hannes Reinecke Cc: #3.12+ Signed-off-by: Nicholas Bellinger --- drivers/target/iscsi/iscsi_target.c | 1 + drivers/target/iscsi/iscsi_target_login.c | 6 ------ 2 files changed, 1 insertion(+), 6 deletions(-) diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c index 02182ab017b1..00867190413c 100644 --- a/drivers/target/iscsi/iscsi_target.c +++ b/drivers/target/iscsi/iscsi_target.c @@ -465,6 +465,7 @@ int iscsit_del_np(struct iscsi_np *np) */ send_sig(SIGINT, np->np_thread, 1); kthread_stop(np->np_thread); + np->np_thread = NULL; } np->np_transport->iscsit_free_np(np); diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c index 4eb93b2b6473..e29279e6b577 100644 --- a/drivers/target/iscsi/iscsi_target_login.c +++ b/drivers/target/iscsi/iscsi_target_login.c @@ -1403,11 +1403,6 @@ old_sess_out: out: stop = kthread_should_stop(); - if (!stop && signal_pending(current)) { - spin_lock_bh(&np->np_thread_lock); - stop = (np->np_thread_state == ISCSI_NP_THREAD_SHUTDOWN); - spin_unlock_bh(&np->np_thread_lock); - } /* Wait for another socket.. */ if (!stop) return 1; @@ -1415,7 +1410,6 @@ exit: iscsi_stop_login_thread_timer(np); spin_lock_bh(&np->np_thread_lock); np->np_thread_state = ISCSI_NP_THREAD_EXIT; - np->np_thread = NULL; spin_unlock_bh(&np->np_thread_lock); return 0; -- 2.34.1