CVEvulnerability
CVE-2026-68182
- Status
- Received
- Published
- 2026-08-10
- Last modified
- 2026-08-19
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Description
In the Linux kernel, the following vulnerability has been resolved:
comedi: comedi_parport: deal with premature interrupt
Syzbot reported a general protection fault in
`comedi_get_is_subdevice_running()`, which was called from the interrupt
handler `parport_interrupt()` in the "comedi_parport" driver, but it
does not currently have a C reproducer for the problem. It's
probably due to a premature interrupt for one of two reasons:
1. The driver sets up the interrupt handler before the comedi subdevices
used by the interrupt handler have been allocated, but does not
disable the interrupt in the parallel port's CTRL register first.
2. The driver uses a user-supplied I/O port base address which Syzbot
would have supplied, but it might not be backed by real parallel port
hardware.
Change the initialization order in the driver's comedi "attach" handler
(`parport_attach()`) so that the hardware registers are initialized
before the interrupt handler is requested. This should prevent
premature interrupts occurring for real hardware.
Also add a test to the interrupt handler to ensure the comedi device is
fully attached and return early if it isn't.
References
- https://git.kernel.org/stable/c/086a9ae3c5df63ec11033a8c0b3f6a1fd295ddd1 git.kernel.org
- https://git.kernel.org/stable/c/17221216ae8ce6a24e8a4e787382e3ebc81b88a8 git.kernel.org
- https://git.kernel.org/stable/c/48ef18e5eb6b8a9c546038b2ab89a841fcd97fe7 git.kernel.org
- https://git.kernel.org/stable/c/5d059ce0e6a2f6f8b97273499d47b8f917097b48 git.kernel.org
- https://git.kernel.org/stable/c/6ed34611e569fc1a1169905c5228fd0eb2806c1b git.kernel.org
- https://git.kernel.org/stable/c/a88b25db815ff6edace81b0bb0f4a201133bd215 git.kernel.org
- https://git.kernel.org/stable/c/b061bb4dca49fd93063359d3805387235818778c git.kernel.org
- https://git.kernel.org/stable/c/cf26dd2d841583c54a87005c4934b92fddb930c3 git.kernel.org