From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
From: Ian Abbott <abbotti@xxxxxxxxx>
commit ac0bbf55ed3be75fde1f8907e91ecd2fd589bde3 upstream.
The digital input subdevice supports Comedi asynchronous commands that
read interrupt status information. This uses 16-bit Comedi samples (of
which only the bottom 8 bits contain status information). However, the
interrupt handler is calling `comedi_buf_write_samples()` with the
address of a 32-bit variable `unsigned int status`. On a bigendian
machine, this will copy 2 bytes from the wrong end of the variable. Fix
it by changing the type of the variable to `unsigned short`.
Fixes: a8c66b684efa ("staging: comedi: addi_apci_1500: rewrite the subdevice support functions")
Cc: <stable@xxxxxxxxxxxxxxx> #4.0+
Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
Link: https://lore.kernel.org/r/20210223143055.257402-3-abbotti@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/addi_apci_1500.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
--- a/drivers/staging/comedi/drivers/addi_apci_1500.c
+++ b/drivers/staging/comedi/drivers/addi_apci_1500.c
@@ -217,7 +217,7 @@ static irqreturn_t apci1500_interrupt(in
struct comedi_device *dev = d;
struct apci1500_private *devpriv = dev->private;
struct comedi_subdevice *s = dev->read_subdev;
- unsigned int status = 0;
+ unsigned short status = 0;
unsigned int val;
val = inl(devpriv->amcc + AMCC_OP_REG_INTCSR);
@@ -247,14 +247,14 @@ static irqreturn_t apci1500_interrupt(in
*
* Mask Meaning
* ---------- ------------------------------------------
- * 0x00000001 Event 1 has occurred
- * 0x00000010 Event 2 has occurred
- * 0x00000100 Counter/timer 1 has run down (not implemented)
- * 0x00001000 Counter/timer 2 has run down (not implemented)
- * 0x00010000 Counter 3 has run down (not implemented)
- * 0x00100000 Watchdog has run down (not implemented)
- * 0x01000000 Voltage error
- * 0x10000000 Short-circuit error
+ * 0b00000001 Event 1 has occurred
+ * 0b00000010 Event 2 has occurred
+ * 0b00000100 Counter/timer 1 has run down (not implemented)
+ * 0b00001000 Counter/timer 2 has run down (not implemented)
+ * 0b00010000 Counter 3 has run down (not implemented)
+ * 0b00100000 Watchdog has run down (not implemented)
+ * 0b01000000 Voltage error
+ * 0b10000000 Short-circuit error
*/
comedi_buf_write_samples(s, &status, 1);
comedi_handle_events(dev, s);
