From: Greg Kroah-Hartman gregkh@linuxfoundation.org
From: Ian Abbott abbotti@mev.co.uk
commit 25317f428a78fde71b2bf3f24d05850f08a73a52 upstream.
The Change-Of-State (COS) subdevice supports Comedi asynchronous commands to read 16-bit change-of-state values. However, the interrupt handler is calling `comedi_buf_write_samples()` with the address of a 32-bit integer `&s->state`. On bigendian architectures, it will copy 2 bytes from the wrong end of the 32-bit integer. Fix it by transferring the value via a 16-bit integer.
Fixes: 6bb45f2b0c86 ("staging: comedi: addi_apci_1032: use comedi_buf_write_samples()") Cc: stable@vger.kernel.org # 3.19+ Signed-off-by: Ian Abbott abbotti@mev.co.uk Link: https://lore.kernel.org/r/20210223143055.257402-2-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/staging/comedi/drivers/addi_apci_1032.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/staging/comedi/drivers/addi_apci_1032.c +++ b/drivers/staging/comedi/drivers/addi_apci_1032.c @@ -269,6 +269,7 @@ static irqreturn_t apci1032_interrupt(in struct apci1032_private *devpriv = dev->private; struct comedi_subdevice *s = dev->read_subdev; unsigned int ctrl; + unsigned short val;
/* check interrupt is from this device */ if ((inl(devpriv->amcc_iobase + AMCC_OP_REG_INTCSR) & @@ -284,7 +285,8 @@ static irqreturn_t apci1032_interrupt(in outl(ctrl & ~APCI1032_CTRL_INT_ENA, dev->iobase + APCI1032_CTRL_REG);
s->state = inl(dev->iobase + APCI1032_STATUS_REG) & 0xffff; - comedi_buf_write_samples(s, &s->state, 1); + val = s->state; + comedi_buf_write_samples(s, &val, 1); comedi_handle_events(dev, s);
/* enable the interrupt */