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| author | Ian Abbott <abbotti@mev.co.uk> | 2025-07-07 16:09:08 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-07-16 16:02:26 +0300 |
| commit | ed93c6f68a3be06e4e0c331c6e751f462dee3932 (patch) | |
| tree | 937bce6849da9fa0ef450bfa65343d39866eb0fd /drivers/comedi | |
| parent | ab705c8c35e18652abc6239c07cf3441f03e2cda (diff) | |
| download | linux-ed93c6f68a3be06e4e0c331c6e751f462dee3932.tar.xz | |
comedi: das16m1: Fix bit shift out of bounds
When checking for a supported IRQ number, the following test is used:
/* only irqs 2, 3, 4, 5, 6, 7, 10, 11, 12, 14, and 15 are valid */
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.
Reported-by: syzbot+c52293513298e0fd9a94@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=c52293513298e0fd9a94
Fixes: 729988507680 ("staging: comedi: das16m1: tidy up the irq support in das16m1_attach()")
Tested-by: syzbot+c52293513298e0fd9a94@syzkaller.appspotmail.com
Suggested-by: "Enju, Kohei" <enjuk@amazon.co.jp>
Cc: stable@vger.kernel.org # 5.13+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20250707130908.70758-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/comedi')
| -rw-r--r-- | drivers/comedi/drivers/das16m1.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/comedi/drivers/das16m1.c b/drivers/comedi/drivers/das16m1.c index b8ea737ad3d1..1b638f5b5a4f 100644 --- a/drivers/comedi/drivers/das16m1.c +++ b/drivers/comedi/drivers/das16m1.c @@ -522,7 +522,8 @@ static int das16m1_attach(struct comedi_device *dev, devpriv->extra_iobase = dev->iobase + DAS16M1_8255_IOBASE; /* only irqs 2, 3, 4, 5, 6, 7, 10, 11, 12, 14, and 15 are valid */ - if ((1 << it->options[1]) & 0xdcfc) { + if (it->options[1] >= 2 && it->options[1] <= 15 && + (1 << it->options[1]) & 0xdcfc) { ret = request_irq(it->options[1], das16m1_interrupt, 0, dev->board_name, dev); if (ret == 0) |