CVE-2026-89769 clocksource/drivers/nxp-pit: Fix IRQ leak on cpuhp_setup_state error path
A use-after-free vulnerability in the NXP PIT clocksource driver allows attackers to potentially execute code or cause a denial of service via an IRQ leak.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-89769?
CVE-2026-89769 is a high-severity use after free vulnerability in Linux, published on 11 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
clocksource/drivers/nxp-pit: Fix IRQ leak on cpuhp_setup_state error path
When cpuhp_setup_state fails after pit_clockevent_per_cpu_init has successfully called request_irq, the error handling jumps directly to out_pit_clocksource_unregister without freeing the registered IRQ.
This leaks the IRQ line and, since kfree(pit) follows, leaves a dangling pointer registered as the interrupt handler's dev_id, potentially leading to a use-after-free if the IRQ fires afterwards.
Fix it by calling pit_clockevent_per_cpu_exit to properly release the IRQ before falling through to the existing cleanup chain.
Which versions are affected by CVE-2026-89769?
How do I fix CVE-2026-89769?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-89769 being exploited?
There is no known exploitation of CVE-2026-89769 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-89769, DEBIAN-CVE-2026-89769, GHSA-8vp9-2h56-3438, UBUNTU-CVE-2026-89769.