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;