[ Upstream commit ed93c6f68a3be06e4e0c331c6e751f462dee3932 ]
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 --- drivers/staging/comedi/drivers/das16m1.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/comedi/drivers/das16m1.c b/drivers/staging/comedi/drivers/das16m1.c index 75f3dbbe97ac..0d54387a1c26 100644 --- a/drivers/staging/comedi/drivers/das16m1.c +++ b/drivers/staging/comedi/drivers/das16m1.c @@ -523,7 +523,8 @@ 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)
[ Sasha's backport helper bot ]
Hi,
✅ All tests passed successfully. No issues detected. No action required from the submitter.
The upstream commit SHA1 provided is correct: ed93c6f68a3be06e4e0c331c6e751f462dee3932
Status in newer kernel trees: 6.15.y | Not found 6.12.y | Not found 6.6.y | Not found 6.1.y | Not found 5.15.y | Not found
Note: The patch differs from the upstream commit: --- 1: ed93c6f68a3b ! 1: cd8b98d5fa76 comedi: das16m1: Fix bit shift out of bounds @@ Metadata ## Commit message ## comedi: das16m1: Fix bit shift out of bounds
+ [ Upstream commit ed93c6f68a3be06e4e0c331c6e751f462dee3932 ] + 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 */ @@ Commit message Link: https://lore.kernel.org/r/20250707130908.70758-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
- ## drivers/comedi/drivers/das16m1.c ## -@@ drivers/comedi/drivers/das16m1.c: static int das16m1_attach(struct comedi_device *dev, + ## drivers/staging/comedi/drivers/das16m1.c ## +@@ drivers/staging/comedi/drivers/das16m1.c: 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 */
---
Results of testing on various branches:
| Branch | Patch Apply | Build Test | |---------------------------|-------------|------------| | origin/linux-5.10.y | Success | Success |
linux-stable-mirror@lists.linaro.org