Bug 2468253 (CVE-2026-43426)

Summary:	CVE-2026-43426 kernel: usb: renesas_usbhs: fix use-after-free in ISR during device removal
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	unspecified	CC:	rhel-process-autobot, 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 `renesas_usbhs` driver. This vulnerability occurs during the removal of a USB device, where the driver frees memory resources before fully unregistering its interrupt handler. If an interrupt fires during this critical window, the interrupt service routine (ISR) attempts to access memory that has already been deallocated, leading to a use-after-free condition. This can result in system instability or a denial of service (DoS).	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 2026-05-08 15:07:12 UTC

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

usb: renesas_usbhs: fix use-after-free in ISR during device removal

In usbhs_remove(), the driver frees resources (including the pipe array)
while the interrupt handler (usbhs_interrupt) is still registered. If an
interrupt fires after usbhs_pipe_remove() but before the driver is fully
unbound, the ISR may access freed memory, causing a use-after-free.

Fix this by calling devm_free_irq() before freeing resources. This ensures
the interrupt handler is both disabled and synchronized (waits for any
running ISR to complete) before usbhs_pipe_remove() is called.

Comment 1 Alexander B 2026-05-08 16:52:40 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050849-CVE-2026-43426-eef1@gregkh/T