Bug 2546457 (CVE-2026-98210)

Summary:	CVE-2026-98210 kernel: mmc: mxcmmc: cancel data work and watchdog 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's mxcmmc host driver. A local user with administrative privileges could trigger this vulnerability by unbinding or removing the device, leading to a Denial of Service (DoS) or potential arbitrary code execution. The driver fails to cancel active background tasks and watchdog timers before freeing host resources during device removal, resulting in a use-after-free condition when a pending task or timer fires and accesses 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 2026-10-06 09:23:33 UTC

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

mmc: mxcmmc: cancel data work and watchdog on remove

mxcmci_remove() frees the host through the devm tail, but neither it nor
mmc_remove_host() drains the driver's own asynchronous state.
host->watchdog, a 10 s timer armed on the DMA path in mxcmci_setup_data(),
is deleted only by the DMA- and IRQ-complete paths, which the remove path
does not explicitly drain; it can therefore fire after the host is freed
and dereference it in mxcmci_watchdog().  host->datawork, armed from the
IRQ handler on the PIO path, is not cancelled by the remove path either.

Free the devm-registered IRQ, then cancel datawork and delete the watchdog
in mxcmci_remove(), before dma_release_channel().  Freeing the IRQ first
keeps a trailing handler from re-arming datawork between the cancel and
the host free.  Both callbacks are non-self-rearming.

This issue was found by an in-house static analysis tool.

Comment 1 Mauro Matteo Cascella 2026-10-09 09:07:14 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98210.mbox