qla2xxx: Fix stale pointer access.

[ Upstream Commit 84e32a06f4f8756ce9ec3c8dc7e97896575f0771 ]

Commit 84e32a0 ("qla2xxx: Use pci_enable_msix_range() instead of
pci_enable_msix()") introduced a regression when target mode is enabled.
In qla24xx_enable_msix(), ha->max_rsp_queues was incorrectly set
to a value higher than the number of response queues allocated causing
an invalid dereference. Specifically here in qla2x00_init_rings():
    *rsp->in_ptr = 0;

Add additional check to make sure the pointer is valid. following
call stack will be seen

---- 8< ----
RIP: 0010:[<ffffffffa02ccadc>]  [<ffffffffa02ccadc>] qla2x00_init_rings+0xdc/0x320 [qla2xxx]
RSP: 0018:ffff880429447dd8  EFLAGS: 00010082
....
Call Trace:
[<ffffffffa02ceb40>] qla2x00_abort_isp+0x170/0x6b0 [qla2xxx]
[<ffffffffa02c6f77>] qla2x00_do_dpc+0x357/0x7f0 [qla2xxx]
[<ffffffffa02c6c20>] ? qla2x00_relogin+0x260/0x260 [qla2xxx]
[<ffffffff8107d2c9>] kthread+0xc9/0xe0
[<ffffffff8107d200>] ? flush_kthread_worker+0x90/0x90
[<ffffffff8172cc6f>] ret_from_fork+0x3f/0x70
[<ffffffff8107d200>] ? flush_kthread_worker+0x90/0x90
---- 8< ----

Cc: <stable@vger.kernel.org>
Signed-off-by: Quinn Tran <quinn.tran@qlogic.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c
index 52a8765..692a757 100644
--- a/drivers/scsi/qla2xxx/qla_init.c
+++ b/drivers/scsi/qla2xxx/qla_init.c
@@ -2204,7 +2204,7 @@
 	/* Clear outstanding commands array. */
 	for (que = 0; que < ha->max_req_queues; que++) {
 		req = ha->req_q_map[que];
-		if (!req)
+		if (!req || !test_bit(que, ha->req_qid_map))
 			continue;
 		req->out_ptr = (void *)(req->ring + req->length);
 		*req->out_ptr = 0;
@@ -2221,7 +2221,7 @@
 
 	for (que = 0; que < ha->max_rsp_queues; que++) {
 		rsp = ha->rsp_q_map[que];
-		if (!rsp)
+		if (!rsp || !test_bit(que, ha->rsp_qid_map))
 			continue;
 		rsp->in_ptr = (void *)(rsp->ring + rsp->length);
 		*rsp->in_ptr = 0;
@@ -4981,7 +4981,7 @@
 
 	for (i = 1; i < ha->max_rsp_queues; i++) {
 		rsp = ha->rsp_q_map[i];
-		if (rsp) {
+		if (rsp && test_bit(i, ha->rsp_qid_map)) {
 			rsp->options &= ~BIT_0;
 			ret = qla25xx_init_rsp_que(base_vha, rsp);
 			if (ret != QLA_SUCCESS)
@@ -4996,8 +4996,8 @@
 	}
 	for (i = 1; i < ha->max_req_queues; i++) {
 		req = ha->req_q_map[i];
-		if (req) {
-		/* Clear outstanding commands array. */
+		if (req && test_bit(i, ha->req_qid_map)) {
+			/* Clear outstanding commands array. */
 			req->options &= ~BIT_0;
 			ret = qla25xx_init_req_que(base_vha, req);
 			if (ret != QLA_SUCCESS)