staging: comedi: drivers: properly validate cmd->scan_end_arg

When the async command 'scan_end_src' is TRIG_COUNT the 'scan_end_arg'
is the cmd->chanlist_len. Fix a couple open-coded drivers. Add the
check to the drivers that do not validate this command argument.

The core validates that the cmd->chanlist_len is <= s->len_chanlist.
During the post config after the attach the core also make sure that
the s->len_chanlist is initialized. For clarity, initialize the
s->len_chanlist in a couple drivers that are relying on the core to
initialize it to '1'.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/8255.c

@@ -231,7 +231,7 @@ static int subdev_8255_cmdtest(struct comedi_device *dev,
 	err |= cfc_check_trigger_arg_is(&cmd->start_arg, 0);
 	err |= cfc_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
 	err |= cfc_check_trigger_arg_is(&cmd->convert_arg, 0);
-	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, 1);
+	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);
 	err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0);
 
 	if (err)
@@ -298,6 +298,7 @@ int subdev_8255_init_irq(struct comedi_device *dev, struct comedi_subdevice *s,
 	if (ret)
 		return ret;
 
+	s->len_chanlist	= 1;
 	s->do_cmdtest	= subdev_8255_cmdtest;
 	s->do_cmd	= subdev_8255_cmd;
 	s->cancel	= subdev_8255_cancel;

drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c

@@ -778,6 +778,7 @@ static int apci3120_ai_cmdtest(struct comedi_device *dev,
 	}
 
 	err |= cfc_check_trigger_arg_min(&cmd->chanlist_len, 1);
+	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);
 
 	if (cmd->stop_src == TRIG_COUNT)
 		err |= cfc_check_trigger_arg_min(&cmd->stop_arg, 1);

drivers/staging/comedi/drivers/addi-data/hwdrv_apci3200.c

@@ -2270,6 +2270,11 @@ static int apci3200_ai_cmdtest(struct comedi_device *dev,
 		apci3200_reset(dev);
 		return 2;
 	}
+
+	/* Step 3: check if arguments are trivially valid */
+
+	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);
+
 	/* i_FirstChannel=cmd->chanlist[0]; */
 	s_BoardInfos[dev->minor].i_FirstChannel = cmd->chanlist[0];
 	/* i_LastChannel=cmd->chanlist[1]; */

drivers/staging/comedi/drivers/addi_apci_1032.c

@@ -198,7 +198,7 @@ static int apci1032_cos_cmdtest(struct comedi_device *dev,
 	err |= cfc_check_trigger_arg_is(&cmd->start_arg, 0);
 	err |= cfc_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
 	err |= cfc_check_trigger_arg_is(&cmd->convert_arg, 0);
-	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, 1);
+	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);
 	err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0);
 
 	if (err)
@@ -332,6 +332,7 @@ static int apci1032_auto_attach(struct comedi_device *dev,
 		s->range_table	= &range_digital;
 		s->insn_config	= apci1032_cos_insn_config;
 		s->insn_bits	= apci1032_cos_insn_bits;
+		s->len_chanlist	= 1;
 		s->do_cmdtest	= apci1032_cos_cmdtest;
 		s->do_cmd	= apci1032_cos_cmd;
 		s->cancel	= apci1032_cos_cancel;

drivers/staging/comedi/drivers/amplc_pc236.c

@@ -314,7 +314,7 @@ static int pc236_intr_cmdtest(struct comedi_device *dev,
 	err |= cfc_check_trigger_arg_is(&cmd->start_arg, 0);
 	err |= cfc_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
 	err |= cfc_check_trigger_arg_is(&cmd->convert_arg, 0);
-	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, 1);
+	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);
 	err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0);
 
 	if (err)
@@ -402,6 +402,7 @@ static int pc236_common_attach(struct comedi_device *dev, unsigned long iobase,
 			s->maxdata = 1;
 			s->range_table = &range_digital;
 			s->insn_bits = pc236_intr_insn;
+			s->len_chanlist	= 1;
 			s->do_cmdtest = pc236_intr_cmdtest;
 			s->do_cmd = pc236_intr_cmd;
 			s->cancel = pc236_intr_cancel;

drivers/staging/comedi/drivers/comedi_parport.c

@@ -181,7 +181,7 @@ static int parport_intr_cmdtest(struct comedi_device *dev,
 	err |= cfc_check_trigger_arg_is(&cmd->start_arg, 0);
 	err |= cfc_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
 	err |= cfc_check_trigger_arg_is(&cmd->convert_arg, 0);
-	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, 1);
+	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);
 	err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0);
 
 	if (err)
@@ -295,6 +295,7 @@ static int parport_attach(struct comedi_device *dev,
 		s->maxdata	= 1;
 		s->range_table	= &range_digital;
 		s->insn_bits	= parport_intr_insn_bits;
+		s->len_chanlist	= 1;
 		s->do_cmdtest	= parport_intr_cmdtest;
 		s->do_cmd	= parport_intr_cmd;
 		s->cancel	= parport_intr_cancel;

drivers/staging/comedi/drivers/dt282x.c

@@ -852,7 +852,7 @@ static int dt282x_ao_cmdtest(struct comedi_device *dev,
 	err |= cfc_check_trigger_arg_is(&cmd->start_arg, 0);
 	err |= cfc_check_trigger_arg_min(&cmd->scan_begin_arg, 5000);
 	err |= cfc_check_trigger_arg_is(&cmd->convert_arg, 0);
-	err |= cfc_check_trigger_arg_max(&cmd->scan_end_arg, 2);
+	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);
 
 	if (cmd->stop_src == TRIG_COUNT) {
 		/* any count is allowed */

drivers/staging/comedi/drivers/ni_6527.c

@@ -253,7 +253,7 @@ static int ni6527_intr_cmdtest(struct comedi_device *dev,
 	err |= cfc_check_trigger_arg_is(&cmd->start_arg, 0);
 	err |= cfc_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
 	err |= cfc_check_trigger_arg_is(&cmd->convert_arg, 0);
-	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, 1);
+	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);
 	err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0);
 
 	if (err)
@@ -421,6 +421,7 @@ static int ni6527_auto_attach(struct comedi_device *dev,
 		s->range_table	= &range_digital;
 		s->insn_config	= ni6527_intr_insn_config;
 		s->insn_bits	= ni6527_intr_insn_bits;
+		s->len_chanlist	= 1;
 		s->do_cmdtest	= ni6527_intr_cmdtest;
 		s->do_cmd	= ni6527_intr_cmd;
 		s->cancel	= ni6527_intr_cancel;

drivers/staging/comedi/drivers/ni_65xx.c

@@ -473,7 +473,7 @@ static int ni_65xx_intr_cmdtest(struct comedi_device *dev,
 	err |= cfc_check_trigger_arg_is(&cmd->start_arg, 0);
 	err |= cfc_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
 	err |= cfc_check_trigger_arg_is(&cmd->convert_arg, 0);
-	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, 1);
+	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);
 	err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0);
 
 	if (err)
@@ -671,6 +671,7 @@ static int ni_65xx_auto_attach(struct comedi_device *dev,
 	s->n_chan = 1;
 	s->range_table = &range_unknown;
 	s->maxdata = 1;
+	s->len_chanlist	= 1;
 	s->do_cmdtest = ni_65xx_intr_cmdtest;
 	s->do_cmd = ni_65xx_intr_cmd;
 	s->cancel = ni_65xx_intr_cancel;

drivers/staging/comedi/drivers/pcl726.c

@@ -197,7 +197,7 @@ static int pcl726_intr_cmdtest(struct comedi_device *dev,
 	err |= cfc_check_trigger_arg_is(&cmd->start_arg, 0);
 	err |= cfc_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
 	err |= cfc_check_trigger_arg_is(&cmd->convert_arg, 0);
-	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, 1);
+	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);
 	err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0);
 
 	if (err)
@@ -430,6 +430,7 @@ static int pcl726_attach(struct comedi_device *dev,
 		s->maxdata	= 1;
 		s->range_table	= &range_digital;
 		s->insn_bits	= pcl726_intr_insn_bits;
+		s->len_chanlist	= 1;
 		s->do_cmdtest	= pcl726_intr_cmdtest;
 		s->do_cmd	= pcl726_intr_cmd;
 		s->cancel	= pcl726_intr_cancel;

drivers/staging/comedi/drivers/rtd520.c

@@ -878,6 +878,8 @@ static int rtd_ai_cmdtest(struct comedi_device *dev,
 		err |= cfc_check_trigger_arg_max(&cmd->convert_arg, 9);
 	}
 
+	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);
+
 	if (cmd->stop_src == TRIG_COUNT) {
 		/* TODO check for rounding error due to counter wrap */
 	} else {