[PATCH 5.15 080/779] scsi: qla2xxx: Zero undefined mailbox IN registers

From: Greg Kroah-Hartman
Date: Mon Aug 15 2022 - 14:22:28 EST


From: Bikash Hazarika <bhazarika@xxxxxxxxxxx>

commit 6c96a3c7d49593ef15805f5e497601c87695abc9 upstream.

While requesting a new mailbox command, driver does not write any data to
unused registers. Initialize the unused register value to zero while
requesting a new mailbox command to prevent stale entry access by firmware.

Link: https://lore.kernel.org/r/20220713052045.10683-4-njavali@xxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx>
Signed-off-by: Bikash Hazarika <bhazarika@xxxxxxxxxxx>
Signed-off-by: Quinn Tran <qutran@xxxxxxxxxxx>
Signed-off-by: Nilesh Javali <njavali@xxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/qla2xxx/qla_mbx.c | 2 ++
1 file changed, 2 insertions(+)

--- a/drivers/scsi/qla2xxx/qla_mbx.c
+++ b/drivers/scsi/qla2xxx/qla_mbx.c
@@ -238,6 +238,8 @@ qla2x00_mailbox_command(scsi_qla_host_t
ql_dbg(ql_dbg_mbx, vha, 0x1112,
"mbox[%d]<-0x%04x\n", cnt, *iptr);
wrt_reg_word(optr, *iptr);
+ } else {
+ wrt_reg_word(optr, 0);
}

mboxes >>= 1;