[PATCH 01/49] staging: comedi: drivers: core validates chanlist_len max

[H Hartley Sweeten]

The comedi core checks if the (cmd->chanlist_len > s->len_chanlist) when the
comedi_cmd is copied from user to kernel space by __comedi_get_user_cmd().
If so, the core returns -EINVAL and will not call the subdevice (*do_cmdtest)
and (*do_cmd).

Remove the unnecessary "max" checks in the comedi driver (*do_cmdtest) and
helper functions.

Signed-off-by: H Hartley Sweeten <hsweeten at visionengravers.com>
Cc: Ian Abbott <abbotti at mev.co.uk>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c | 3 ---
 drivers/staging/comedi/drivers/adl_pci9118.c              | 2 --
 drivers/staging/comedi/drivers/me4000.c                   | 6 ------
 drivers/staging/comedi/drivers/ni_labpc.c                 | 8 --------
 drivers/staging/comedi/drivers/pcl812.c                   | 1 -
 drivers/staging/comedi/drivers/rtd520.c                   | 4 ----
 6 files changed, 24 deletions(-)

diff --git a/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c b/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c
index 70e8f42..66c24e4 100644
--- a/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c
+++ b/drivers/staging/comedi/drivers/addi-data/hwdrv_apci3120.c
@@ -734,7 +734,6 @@ static int apci3120_ai_cmdtest(struct comedi_device *dev,
 			       struct comedi_subdevice *s,
 			       struct comedi_cmd *cmd)
 {
-	const struct addi_board *this_board = comedi_board(dev);
 	int err = 0;
 
 	/* Step 1 : check if triggers are trivially valid */
@@ -779,8 +778,6 @@ static int apci3120_ai_cmdtest(struct comedi_device *dev,
 	}
 
 	err |= cfc_check_trigger_arg_min(&cmd->chanlist_len, 1);
-	err |= cfc_check_trigger_arg_max(&cmd->chanlist_len,
-					 this_board->i_AiChannelList);
 
 	if (cmd->stop_src == TRIG_COUNT)
 		err |= cfc_check_trigger_arg_min(&cmd->stop_arg, 1);
diff --git a/drivers/staging/comedi/drivers/adl_pci9118.c b/drivers/staging/comedi/drivers/adl_pci9118.c
index b6abef6..53bbc59 100644
--- a/drivers/staging/comedi/drivers/adl_pci9118.c
+++ b/drivers/staging/comedi/drivers/adl_pci9118.c
@@ -1259,8 +1259,6 @@ static int pci9118_ai_cmdtest(struct comedi_device *dev,
 		err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0);
 
 	err |= cfc_check_trigger_arg_min(&cmd->chanlist_len, 1);
-	err |= cfc_check_trigger_arg_max(&cmd->chanlist_len,
-					 this_board->n_aichanlist);
 
 	err |= cfc_check_trigger_arg_min(&cmd->scan_end_arg,
 					 cmd->chanlist_len);
diff --git a/drivers/staging/comedi/drivers/me4000.c b/drivers/staging/comedi/drivers/me4000.c
index f02b31b..bd03a15 100644
--- a/drivers/staging/comedi/drivers/me4000.c
+++ b/drivers/staging/comedi/drivers/me4000.c
@@ -611,12 +611,6 @@ static int ai_check_chanlist(struct comedi_device *dev,
 		return -EINVAL;
 	}
 
-	/* Check the channel list size */
-	if (cmd->chanlist_len > ME4000_AI_CHANNEL_LIST_COUNT) {
-		dev_err(dev->class_dev, "Channel list is to large\n");
-		return -EINVAL;
-	}
-
 	/* Check the pointer */
 	if (!cmd->chanlist) {
 		dev_err(dev->class_dev, "NULL pointer to channel list\n");
diff --git a/drivers/staging/comedi/drivers/ni_labpc.c b/drivers/staging/comedi/drivers/ni_labpc.c
index f4216e8..c33b9fc 100644
--- a/drivers/staging/comedi/drivers/ni_labpc.c
+++ b/drivers/staging/comedi/drivers/ni_labpc.c
@@ -558,14 +558,6 @@ static int labpc_ai_chanlist_invalid(const struct comedi_device *dev,
 	if (mode == MODE_SINGLE_CHAN)
 		return 0;
 
-	if (mode == MODE_SINGLE_CHAN_INTERVAL) {
-		if (cmd->chanlist_len > 0xff) {
-			comedi_error(dev,
-				     "ni_labpc: chanlist too long for single channel interval mode\n");
-			return 1;
-		}
-	}
-
 	channel = CR_CHAN(cmd->chanlist[0]);
 	range = CR_RANGE(cmd->chanlist[0]);
 	aref = CR_AREF(cmd->chanlist[0]);
diff --git a/drivers/staging/comedi/drivers/pcl812.c b/drivers/staging/comedi/drivers/pcl812.c
index 5cc01fe..0cf115e 100644
--- a/drivers/staging/comedi/drivers/pcl812.c
+++ b/drivers/staging/comedi/drivers/pcl812.c
@@ -761,7 +761,6 @@ static int pcl812_ai_cmdtest(struct comedi_device *dev,
 		err |= cfc_check_trigger_arg_is(&cmd->convert_arg, 0);
 
 	err |= cfc_check_trigger_arg_min(&cmd->chanlist_len, 1);
-	err |= cfc_check_trigger_arg_max(&cmd->chanlist_len, MAX_CHANLIST_LEN);
 	err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);
 
 	if (cmd->stop_src == TRIG_COUNT)
diff --git a/drivers/staging/comedi/drivers/rtd520.c b/drivers/staging/comedi/drivers/rtd520.c
index cd3fdf9..1b1c166 100644
--- a/drivers/staging/comedi/drivers/rtd520.c
+++ b/drivers/staging/comedi/drivers/rtd520.c
@@ -891,10 +891,6 @@ static int rtd_ai_cmdtest(struct comedi_device *dev,
 
 	/* step 4: fix up any arguments */
 
-	if (cmd->chanlist_len > RTD_MAX_CHANLIST) {
-		cmd->chanlist_len = RTD_MAX_CHANLIST;
-		err++;
-	}
 	if (cmd->scan_begin_src == TRIG_TIMER) {
 		tmp = cmd->scan_begin_arg;
 		rtd_ns_to_timer(&cmd->scan_begin_arg,
-- 
1.8.5.2