Описание
In the Linux kernel, the following vulnerability has been resolved:
vfio/pci: Fix double free in dma-buf feature
The error path through vfio_pci_core_feature_dma_buf() ignores its
own advice to only use dma_buf_put() after dma_buf_export(), instead
falling through the entire unwind chain. In the unlikely event that
we encounter file descriptor exhaustion, this can result in an
unbalanced refcount on the vfio device and double free of allocated
objects.
Avoid this by moving the "put" directly into the error path and return
the errno rather than entering the unwind chain.
A flaw was found in the Linux kernel's vfio/pci dma-buf feature. An issue in the error handling of the vfio_pci_core_feature_dma_buf() function can lead to a double free of allocated memory. This can occur under specific conditions, such as file descriptor exhaustion, potentially causing system instability or a denial of service (DoS).
Отчет
Upstream corrected refcount handling on the dma-buf export error path to prevent double free and device refcount imbalance. Red Hat treats this as a local VFIO PCI hardening issue reachable only under resource pressure. Apply updated kernels; optionally unload vfio_pci where VFIO assignment is unused.
Меры по смягчению последствий
To mitigate this issue, prevent the vfio_pci module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| 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 |
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Дополнительная информация
Статус:
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: vfio/pci: Fix double free in dma-buf feature The error path through vfio_pci_core_feature_dma_buf() ignores its own advice to only use dma_buf_put() after dma_buf_export(), instead falling through the entire unwind chain. In the unlikely event that we encounter file descriptor exhaustion, this can result in an unbalanced refcount on the vfio device and double free of allocated objects. Avoid this by moving the "put" directly into the error path and return the errno rather than entering the unwind chain.
In the Linux kernel, the following vulnerability has been resolved: vfio/pci: Fix double free in dma-buf feature The error path through vfio_pci_core_feature_dma_buf() ignores its own advice to only use dma_buf_put() after dma_buf_export(), instead falling through the entire unwind chain. In the unlikely event that we encounter file descriptor exhaustion, this can result in an unbalanced refcount on the vfio device and double free of allocated objects. Avoid this by moving the "put" directly into the error path and return the errno rather than entering the unwind chain.
In the Linux kernel, the following vulnerability has been resolved: v ...
In the Linux kernel, the following vulnerability has been resolved: vfio/pci: Fix double free in dma-buf feature The error path through vfio_pci_core_feature_dma_buf() ignores its own advice to only use dma_buf_put() after dma_buf_export(), instead falling through the entire unwind chain. In the unlikely event that we encounter file descriptor exhaustion, this can result in an unbalanced refcount on the vfio device and double free of allocated objects. Avoid this by moving the "put" directly into the error path and return the errno rather than entering the unwind chain.
5.5 Medium
CVSS3