Описание
In the Linux kernel, the following vulnerability has been resolved:
virtio: fix use-after-free in unregister_virtio_device()
device_unregister() is device_del() plus put_device(). When the caller
holds no extra reference, that drops the last one and runs the release
callback, which for several transports frees the memory the embedded
struct virtio_device sits in. unregister_virtio_device() then calls
virtio_debug_device_exit(), which reads dev->debugfs_dir out of the freed
object.
Affected transports are the ones whose release callback frees and whose
remove path takes no reference: virtio_mmio, virtio_vdpa, virtio_uml,
mlxbf-tmfifo and virtio_ccw. virtio_pci is unaffected because
virtio_pci_remove() brackets the call with get_device() and put_device().
Remove the debugfs entries before the device can go away. They are only
accessed through the protected debugfs interface, so
debugfs_remove_recursive() waits for in-progress file operations before
returning. Tearing them down while the device is still alive is therefore
safe.
Reproduced on User-Mode Linux with CONFIG_KASAN and CONFIG_VIRTIO_DEBUG
by unbinding a virtio-uml device:
BUG: KASAN: slab-use-after-free in virtio_debug_device_exit+0x36/0x4d
Read of size 8 at addr 00000000616e0b10 by task init/1
__asan_report_load8_noabort
virtio_debug_device_exit+0x36/0x4d
unregister_virtio_device+0x48/0x75
virtio_uml_remove
platform_remove
device_release_driver_internal
unbind_store
Freed by task 1:
kfree
virtio_uml_release_dev
device_release
kobject_put
put_device
device_unregister
With this applied, the report is gone and unbind is clean.
A flaw was found in the Linux kernel's virtio subsystem. A local user can trigger a use-after-free condition when unbinding or removing certain virtual I/O (virtio) devices. This issue occurs because the device memory is freed before its debug filesystem entries are removed, resulting in an invalid read operation. Exploitation of this flaw could allow a local attacker to crash the system, leading to a Denial of Service (DoS), or potentially execute arbitrary code.
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 | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Not affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Not affected | ||
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-9 | Not affected |
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Дополнительная информация
Статус:
EPSS
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: virtio: fix use-after-free in unregister_virtio_device() device_unregister() is device_del() plus put_device(). When the caller holds no extra reference, that drops the last one and runs the release callback, which for several transports frees the memory the embedded struct virtio_device sits in. unregister_virtio_device() then calls virtio_debug_device_exit(), which reads dev->debugfs_dir out of the freed object. Affected transports are the ones whose release callback frees and whose remove path takes no reference: virtio_mmio, virtio_vdpa, virtio_uml, mlxbf-tmfifo and virtio_ccw. virtio_pci is unaffected because virtio_pci_remove() brackets the call with get_device() and put_device(). Remove the debugfs entries before the device can go away. They are only accessed through the protected debugfs interface, so debugfs_remove_recursive() waits for in-progress file operations before returning. Tearing them down while t...
In the Linux kernel, the following vulnerability has been resolved: virtio: fix use-after-free in unregister_virtio_device() device_unregister() is device_del() plus put_device(). When the caller holds no extra reference, that drops the last one and runs the release callback, which for several transports frees the memory the embedded struct virtio_device sits in. unregister_virtio_device() then calls virtio_debug_device_exit(), which reads dev->debugfs_dir out of the freed object. Affected transports are the ones whose release callback frees and whose remove path takes no reference: virtio_mmio, virtio_vdpa, virtio_uml, mlxbf-tmfifo and virtio_ccw. virtio_pci is unaffected because virtio_pci_remove() brackets the call with get_device() and put_device(). Remove the debugfs entries before the device can go away. They are only accessed through the protected debugfs interface, so debugfs_remove_recursive() waits for in-progress file operations before returning. Tearing them down while
In the Linux kernel, the following vulnerability has been resolved: v ...
In the Linux kernel, the following vulnerability has been resolved: virtio: fix use-after-free in unregister_virtio_device() device_unregister() is device_del() plus put_device(). When the caller holds no extra reference, that drops the last one and runs the release callback, which for several transports frees the memory the embedded struct virtio_device sits in. unregister_virtio_device() then calls virtio_debug_device_exit(), which reads dev->debugfs_dir out of the freed object. Affected transports are the ones whose release callback frees and whose remove path takes no reference: virtio_mmio, virtio_vdpa, virtio_uml, mlxbf-tmfifo and virtio_ccw. virtio_pci is unaffected because virtio_pci_remove() brackets the call with get_device() and put_device(). Remove the debugfs entries before the device can go away. They are only accessed through the protected debugfs interface, so debugfs_remove_recursive() waits for in-progress file operations before returning. Tearing them down whi...
ELSA-2026-500374: Unbreakable Enterprise kernel security update (IMPORTANT)
EPSS
5.5 Medium
CVSS3