[ Upstream commit b14b076ce593f72585412fc7fd3747e03a5e3632 ]
When checking for a supported IRQ number, the following test is used:
if ((1 << it->options[1]) & board->irq_bits) {
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.
Reported-by: syzbot+32de323b0addb9e114ff@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=32de323b0addb9e114ff Fixes: fcdb427bc7cf ("Staging: comedi: add pcl821 driver") Cc: stable@vger.kernel.org # 5.13+ Signed-off-by: Ian Abbott abbotti@mev.co.uk Link: https://lore.kernel.org/r/20250707133429.73202-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/staging/comedi/drivers/pcl812.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/comedi/drivers/pcl812.c b/drivers/staging/comedi/drivers/pcl812.c index b87ab3840eee..fc06f284ba74 100644 --- a/drivers/staging/comedi/drivers/pcl812.c +++ b/drivers/staging/comedi/drivers/pcl812.c @@ -1151,7 +1151,8 @@ static int pcl812_attach(struct comedi_device *dev, struct comedi_devconfig *it) if (!dev->pacer) return -ENOMEM;
- if ((1 << it->options[1]) & board->irq_bits) { + if (it->options[1] > 0 && it->options[1] < 16 && + (1 << it->options[1]) & board->irq_bits) { ret = request_irq(it->options[1], pcl812_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: b14b076ce593f72585412fc7fd3747e03a5e3632
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: b14b076ce593 ! 1: 08dbf07f845c comedi: pcl812: Fix bit shift out of bounds @@ Metadata ## Commit message ## comedi: pcl812: Fix bit shift out of bounds
+ [ Upstream commit b14b076ce593f72585412fc7fd3747e03a5e3632 ] + When checking for a supported IRQ number, the following test is used:
if ((1 << it->options[1]) & board->irq_bits) { @@ Commit message Link: https://lore.kernel.org/r/20250707133429.73202-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
- ## drivers/comedi/drivers/pcl812.c ## -@@ drivers/comedi/drivers/pcl812.c: static int pcl812_attach(struct comedi_device *dev, struct comedi_devconfig *it) - if (IS_ERR(dev->pacer)) - return PTR_ERR(dev->pacer); + ## drivers/staging/comedi/drivers/pcl812.c ## +@@ drivers/staging/comedi/drivers/pcl812.c: static int pcl812_attach(struct comedi_device *dev, struct comedi_devconfig *it) + if (!dev->pacer) + return -ENOMEM;
- if ((1 << it->options[1]) & board->irq_bits) { + if (it->options[1] > 0 && it->options[1] < 16 &&
---
Results of testing on various branches:
| Branch | Patch Apply | Build Test | |---------------------------|-------------|------------| | origin/linux-5.10.y | Success | Success |
linux-stable-mirror@lists.linaro.org
-
Ian Abbott -
Sasha Levin