iscsi-target: Avoid rejecting incorrect ITT for Data-Out

This patch changes iscsit_check_dataout_hdr() to dump the incoming
Data-Out payload when the received ITT is not associated with a
WRITE, instead of calling iscsit_reject_cmd() for the non WRITE
ITT descriptor.

This addresses a bug where an initiator sending an Data-Out for
an ITT associated with a READ would end up generating a reject
for the READ, eventually resulting in list corruption.

Reported-by: Santosh Kulkarni <santosh.kulkarni@calsoftinc.com>
Reported-by: Arshad Hussain <arshad.hussain@calsoftinc.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/iscsi/iscsi_target.c

@@ -1309,7 +1309,7 @@ iscsit_check_dataout_hdr(struct iscsi_conn *conn, unsigned char *buf,
 	if (cmd->data_direction != DMA_TO_DEVICE) {
 		pr_err("Command ITT: 0x%08x received DataOUT for a"
 			" NON-WRITE command.\n", cmd->init_task_tag);
-		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR, buf);
+		return iscsit_dump_data_payload(conn, payload_length, 1);
 	}
 	se_cmd = &cmd->se_cmd;
 	iscsit_mod_dataout_timer(cmd);