Описание
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.
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.
Отчет
A moderate-severity use-after-free flaw was found in the Linux kernel VIA SD/MMC host controller driver (mmc: via-sdmmc), which affects Red Hat offerings that ship a Linux kernel containing this driver code. During device removal, disabling the device interrupt and freeing the IRQ prevents new card-detect work from being queued, but card-detect work already queued by the handler (carddet_work) can still run after via_sd_remove() returns. via_sdc_card_detect() recovers the host structure through container_of() and dereferences its MMIO base, so once remove() returns and the host can be freed, that work touches freed memory. A local attacker with low privileges able to trigger removal of the VIA SD/MMC PCI device could exploit this race to crash the kernel, causing a denial of service; confidentiality and integrity are not affected. Red Hat rates this flaw Moderate (CVSS 5.5, CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H) because it requires local access on systems with the affected hardware and impacts availability only. This differs from the upstream severity of Important (CVSS 7.8), which also scores high confidentiality and integrity impacts: the technical evidence shows the consequence is limited to touching freed kernel memory, which can crash the system.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 6 | kernel | Out of support scope | ||
| Red Hat Enterprise Linux 7 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Fix deferred | ||
| Red Hat Enterprise Linux 8 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Fix deferred | ||
| Red Hat Enterprise Linux 9 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Fix deferred | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Fix deferred | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-9 | Fix deferred |
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Дополнительная информация
Статус:
EPSS
5.5 Medium
CVSS3
Связанные уязвимости
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.
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.
In the Linux kernel, the following vulnerability has been resolved: m ...
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.
ELSA-2026-500572: Unbreakable Enterprise kernel security update (IMPORTANT)
EPSS
5.5 Medium
CVSS3