Bug 2562715 (CVE-2026-99189)

Summary:	CVE-2026-99189 kernel: kernel: Denial of Service via race condition during MXC GPIO driver initialization
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	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 General-Purpose Input/Output (GPIO) MXC driver. This vulnerability can result in a Denial of Service (DoS) through a system crash if an interrupt arrives while the device is initializing. Because the interrupt handler is registered before its required data structures are fully set up, or if subsequent initialization steps fail, the system may access uninitialized or freed memory.	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 2026-10-28 10:55:25 UTC

In the Linux kernel, the following vulnerability has been resolved:

gpio: mxc: fix race between chained IRQ handler install and probe completion

mxc_update_irq_chained_handler() is called before the IRQ domain, the
generic IRQ chip, and the port list entry are set up. If an interrupt
arrives in that window:

 - mx3_gpio_irq_handler() calls generic_handle_domain_irq() with
   port->domain still NULL.
 - mx2_gpio_irq_handler() walks mxc_gpio_ports, but the port has not
   been added to the list yet.

Additionally, if any of the subsequent probe steps
(gpio_generic_chip_init(), devm_gpiochip_add_data(),
irq_domain_create_legacy(), or mxc_gpio_init_gc()) fail, the error
paths never unregister the chained handler, leaving a dangling handler
that points at freed memory.

Move the handler installation after all its dependencies are ready and
after list_add_tail(), so the handler is never live while the data
structures it touches are incomplete, and is never installed if probe
fails.