Bug 2532479 (CVE-2026-89441)

Summary:	CVE-2026-89441 kernel: mmc: via-sdmmc: cancel card-detect work on remove
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, specifically within the `mmc: via-sdmmc` driver responsible for managing SD and MultiMediaCard (MMC) devices. This vulnerability occurs during device removal, where a timing issue allows a process to attempt to access memory that has already been released. This unauthorized memory access can lead to system instability or cause the system to crash, resulting in a denial of service.	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 23:24:08 UTC

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

mmc: via-sdmmc: cancel card-detect work on remove

Disabling the device interrupt and freeing the IRQ prevents new card-detect
work from being queued, but carddet_work already queued by the handler can
still run after via_sd_remove() returns. via_sdc_card_detect() recovers the
host through container_of() and dereferences its MMIO base; once remove()
returns the host can be freed, so that work would touch freed memory.

Cancel carddet_work after freeing the IRQ and before cancelling
finish_bh_work, which the card-detect handler can also queue. carddet_work
can re-enable the interrupt through via_reset_pcictrl(); mask it again
afterwards.

This issue was found by an in-house static analysis tool and confirmed by
manual code review.

Comment 1 Keith Grant 2026-09-14 21:36:45 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89441.mbox