From: Greg Kroah-Hartman gregkh@linuxfoundation.org
From: Ian Abbott abbotti@mev.co.uk
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@vger.kernel.org #4.0+ Signed-off-by: Ian Abbott abbotti@mev.co.uk Link: https://lore.kernel.org/r/20210223143055.257402-3-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 @@ -208,7 +208,7 @@ 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); @@ -238,14 +238,14 @@ 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);