Bug 2532121 (CVE-2026-89440)

Summary: CVE-2026-89440 kernel: mmc: via-sdmmc: stop card-detect handling on probe failure
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   
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Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's mmc: via-sdmmc component. During the probe process, if the `mmc_add_host()` function fails, the SD card-detect interrupt handler continues to operate on memory that has already been released. This can lead to memory corruption, potentially allowing a local attacker to cause system instability or execute unauthorized code.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-09-11 20:46:18 UTC 
In the Linux kernel, the following vulnerability has been resolved:

mmc: via-sdmmc: stop card-detect handling on probe failure

request_irq() registers the SD card-detect interrupt and the probe enables
it before mmc_add_host() runs. If mmc_add_host() fails, the error path only
unmaps the registers and returns: the interrupt stays registered, so the
handler keeps running against the host once it is freed. via_sdc_isr()
dereferences sdhost and its MMIO base and schedules carddet_work, which
via_sdc_card_detect() also runs against freed memory through its
container_of() dereference.

Add a probe-error path that disables and frees the interrupt and cancels
carddet_work before unmapping. carddet_work can re-enable the device
interrupt via via_reset_pcictrl(), which restores PCIINTCTRL, so mask it
again after cancelling the work.

This issue was found by an in-house static analysis tool and confirmed by
manual code review.
Comment 1 Keith Grant 2026-09-14 21:32:33 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89440.mbox