FAILED: patch "[PATCH] scsi: qla2xxx: Fix response queue handler reading stale" failed to apply to 5.15-stable tree

FAILED: patch "[PATCH] scsi: qla2xxx: Fix response queue handler reading stale" failed to apply to 5.15-stable tree

[gregkh]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.


thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From e4f8a29deb3ba30e414dfb6b09e3ae3bf6dbe74a Mon Sep 17 00:00:00 2001
From: Arun Easi <aeasi@marvell.com>
Date: Fri, 26 Aug 2022 03:25:54 -0700
Subject: [PATCH] scsi: qla2xxx: Fix response queue handler reading stale
 packets

On some platforms, the current logic of relying on finding new packet
solely based on signature pattern can lead to driver reading stale
packets. Though this is a bug in those platforms, reduce such exposures by
limiting reading packets until the IN pointer.

Link: https://lore.kernel.org/r/20220826102559.17474-3-njavali@marvell.com
Cc: stable@vger.kernel.org
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Arun Easi <aeasi@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
index ede76357ccb6..e19fde304e5c 100644
--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -3763,7 +3763,8 @@ void qla24xx_process_response_queue(struct scsi_qla_host *vha,
 	struct qla_hw_data *ha = vha->hw;
 	struct purex_entry_24xx *purex_entry;
 	struct purex_item *pure_item;
-	u16 cur_ring_index;
+	u16 rsp_in = 0, cur_ring_index;
+	int is_shadow_hba;
 
 	if (!ha->flags.fw_started)
 		return;
@@ -3773,7 +3774,18 @@ void qla24xx_process_response_queue(struct scsi_qla_host *vha,
 		qla_cpu_update(rsp->qpair, smp_processor_id());
 	}
 
-	while (rsp->ring_ptr->signature != RESPONSE_PROCESSED) {
+#define __update_rsp_in(_is_shadow_hba, _rsp, _rsp_in)			\
+	do {								\
+		_rsp_in = _is_shadow_hba ? *(_rsp)->in_ptr :		\
+				rd_reg_dword_relaxed((_rsp)->rsp_q_in);	\
+	} while (0)
+
+	is_shadow_hba = IS_SHADOW_REG_CAPABLE(ha);
+
+	__update_rsp_in(is_shadow_hba, rsp, rsp_in);
+
+	while (rsp->ring_index != rsp_in &&
+		       rsp->ring_ptr->signature != RESPONSE_PROCESSED) {
 		pkt = (struct sts_entry_24xx *)rsp->ring_ptr;
 		cur_ring_index = rsp->ring_index;
 
@@ -3887,6 +3899,7 @@ void qla24xx_process_response_queue(struct scsi_qla_host *vha,
 				}
 				pure_item = qla27xx_copy_fpin_pkt(vha,
 							  (void **)&pkt, &rsp);
+				__update_rsp_in(is_shadow_hba, rsp, rsp_in);
 				if (!pure_item)
 					break;
 				qla24xx_queue_purex_item(vha, pure_item,