5.15-stable review patch. If anyone has any objections, please let me know.
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From: Ian Abbott abbotti@mev.co.uk
commit 66acb1586737a22dd7b78abc63213b1bcaa100e4 upstream.
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 Link: https://lore.kernel.org/r/20250707134622.75403-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/comedi/drivers/aio_iiro_16.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/comedi/drivers/aio_iiro_16.c +++ b/drivers/comedi/drivers/aio_iiro_16.c @@ -178,7 +178,8 @@ static int aio_iiro_16_attach(struct com * 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)