When checking for a supported IRQ number, the following test is used:
if ((1 << it->options[1]) & 0xdcfc) {
However, `it->options[i]` is an unchecked `int` value from userspace, so the shift amount could be negative or out of bounds. Fix the test by requiring `it->options[1]` to be within bounds before proceeding with the original test. Valid `it->options[1]` values that select the IRQ will be in the range [1,15]. The value 0 explicitly disables the use of interrupts.
Fixes: ad7a370c8be4 ("staging: comedi: aio_iiro_16: add command support for change of state detection") Cc: stable@vger.kernel.org # 5.13+ Signed-off-by: Ian Abbott abbotti@mev.co.uk --- Patch does not apply cleanly to longterm kernels 5.4.x and 5.10.x. --- drivers/comedi/drivers/aio_iiro_16.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/comedi/drivers/aio_iiro_16.c b/drivers/comedi/drivers/aio_iiro_16.c index b00fab0b89d4..739cc4db52ac 100644 --- a/drivers/comedi/drivers/aio_iiro_16.c +++ b/drivers/comedi/drivers/aio_iiro_16.c @@ -177,7 +177,8 @@ static int aio_iiro_16_attach(struct comedi_device *dev, * Digital input change of state interrupts are optionally supported * using IRQ 2-7, 10-12, 14, or 15. */ - if ((1 << it->options[1]) & 0xdcfc) { + if (it->options[1] > 0 && it->options[1] < 16 && + (1 << it->options[1]) & 0xdcfc) { ret = request_irq(it->options[1], aio_iiro_16_cos, 0, dev->board_name, dev); if (ret == 0)