[PATCH 4.14 177/191] scsi: qedi: Fix list_del corruption while removing active I/O

[Greg Kroah-Hartman]

From: Nilesh Javali <njavali@xxxxxxxxxxx>

[ Upstream commit 28b35d17f9f8573d4646dd8df08917a4076a6b63 ]

While aborting the I/O, the firmware cleanup task timed out and driver
deleted the I/O from active command list. Some time later the firmware
sent the cleanup task response and driver again deleted the I/O from
active command list causing firmware to send completion for non-existent
I/O and list_del corruption of active command list.

Add fix to check if I/O is present before deleting it from the active
command list to ensure firmware sends valid I/O completion and protect
against list_del corruption.

Link: https://lore.kernel.org/r/20200908095657.26821-4-mrangankar@xxxxxxxxxxx
Signed-off-by: Nilesh Javali <njavali@xxxxxxxxxxx>
Signed-off-by: Manish Rangankar <mrangankar@xxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/scsi/qedi/qedi_fw.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/qedi/qedi_fw.c b/drivers/scsi/qedi/qedi_fw.c
index e688300faeefd..e8f2c662471e0 100644
--- a/drivers/scsi/qedi/qedi_fw.c
+++ b/drivers/scsi/qedi/qedi_fw.c
@@ -844,8 +844,11 @@ static void qedi_process_cmd_cleanup_resp(struct qedi_ctx *qedi,
 			qedi_clear_task_idx(qedi_conn->qedi, rtid);
 
 			spin_lock(&qedi_conn->list_lock);
-			list_del_init(&dbg_cmd->io_cmd);
-			qedi_conn->active_cmd_count--;
+			if (likely(dbg_cmd->io_cmd_in_list)) {
+				dbg_cmd->io_cmd_in_list = false;
+				list_del_init(&dbg_cmd->io_cmd);
+				qedi_conn->active_cmd_count--;
+			}
 			spin_unlock(&qedi_conn->list_lock);
 			qedi_cmd->state = CLEANUP_RECV;
 			wake_up_interruptible(&qedi_conn->wait_queue);
@@ -1265,6 +1268,7 @@ int qedi_cleanup_all_io(struct qedi_ctx *qedi, struct qedi_conn *qedi_conn,
 		qedi_conn->cmd_cleanup_req++;
 		qedi_iscsi_cleanup_task(ctask, true);
 
+		cmd->io_cmd_in_list = false;
 		list_del_init(&cmd->io_cmd);
 		qedi_conn->active_cmd_count--;
 		QEDI_WARN(&qedi->dbg_ctx,
@@ -1478,8 +1482,11 @@ static void qedi_tmf_work(struct work_struct *work)
 	spin_unlock_bh(&qedi_conn->tmf_work_lock);
 
 	spin_lock(&qedi_conn->list_lock);
-	list_del_init(&cmd->io_cmd);
-	qedi_conn->active_cmd_count--;
+	if (likely(cmd->io_cmd_in_list)) {
+		cmd->io_cmd_in_list = false;
+		list_del_init(&cmd->io_cmd);
+		qedi_conn->active_cmd_count--;
+	}
 	spin_unlock(&qedi_conn->list_lock);
 
 	clear_bit(QEDI_CONN_FW_CLEANUP, &qedi_conn->flags);
-- 
2.25.1