Bug 2532161 (CVE-2026-89769)

Summary: CVE-2026-89769 kernel: clocksource/drivers/nxp-pit: Fix IRQ leak on cpuhp_setup_state error path
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's NXP PIT (Programmable Interrupt Timer) clocksource driver. When the CPU hotplug setup fails after an interrupt request (IRQ) has been successfully registered, the error handling does not properly free the IRQ. This oversight results in a leaked IRQ line and a dangling pointer, which could lead to a use-after-free vulnerability if the IRQ is subsequently triggered. A local attacker could potentially exploit this to cause system instability or execute arbitrary code.
 Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-11 21:02:44 UTC 
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.
Comment 1 Keith Grant 2026-09-21 18:21:28 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89769.mbox