[ Upstream commit 70f2b28b5243df557f51c054c20058ae207baaac ]

When checking for a supported IRQ number, the following test is used:

/* IRQs 2,3,5,6,7, 10,11,15 are valid for "enhanced" mode */ if ((1 << it->options[1]) & 0x8cec) {

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: 79e5e6addbb1 ("staging: comedi: das6402: rewrite broken driver") Cc: stable@vger.kernel.org # 5.13+ Signed-off-by: Ian Abbott abbotti@mev.co.uk Link: https://lore.kernel.org/r/20250707135737.77448-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/staging/comedi/drivers/das6402.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/comedi/drivers/das6402.c b/drivers/staging/comedi/drivers/das6402.c index 0034005bdf8f..0cd5d1b1ffde 100644 --- a/drivers/staging/comedi/drivers/das6402.c +++ b/drivers/staging/comedi/drivers/das6402.c @@ -569,7 +569,8 @@ static int das6402_attach(struct comedi_device *dev, das6402_reset(dev);

/* IRQs 2,3,5,6,7, 10,11,15 are valid for "enhanced" mode */ - if ((1 << it->options[1]) & 0x8cec) { + if (it->options[1] > 0 && it->options[1] < 16 && + (1 << it->options[1]) & 0x8cec) { ret = request_irq(it->options[1], das6402_interrupt, 0, dev->board_name, dev); if (ret == 0) {