Описание
In the Linux kernel, the following vulnerability has been resolved:
wifi: brcmsmac: fix UAF in brcms_free_timer()
brcms_free_timer() calls brcms_del_timer() which uses the non-synchronous
cancel_delayed_work() to cancel the timer's underlying delayed work. If
the work callback (_brcms_timer) is already running, cancel_delayed_work()
returns false without waiting, and brcms_free_timer() proceeds to kfree(t)
while the callback still accesses t through container_of().
Add an explicit cancel_delayed_work_sync() after brcms_del_timer() to
guarantee that any in-flight callback has completed before the timer
structure is freed.
A flaw was found in the Linux kernel's brcmsmac wireless driver. When a timer is released, the driver fails to wait for running background tasks associated with the timer to finish before freeing memory. A local attacker could exploit this race condition to trigger a use-after-free condition, leading to a system crash, denial of service (DoS), or potentially arbitrary code execution.
Отчет
A race in brcms_free_timer() can cause use after free because brcms_del_timer() uses non synchronous delayed work cancellation and does not wait for an active _brcms_timer callback to finish. The timer structure can therefore be freed while the callback still derives and accesses the same object through container_of(). The confirmed impact is at least a local denial of service through a kernel crash. For the CVSS the PR:L value is used for the paranoid score because delegated network administration or a restricted service may be able to initiate interface lifecycle operations without having full host control. Triggering requires brcmsmac hardware and a narrow race between delayed work execution and timer teardown, so AC:H is appropriate. The issue is not directly network reachable. Remote wireless traffic may influence callback timing but is not known to be sufficient to free the timer object.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options don't 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 | 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 | ||
| 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
4.7 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: wifi: brcmsmac: fix UAF in brcms_free_timer() brcms_free_timer() calls brcms_del_timer() which uses the non-synchronous cancel_delayed_work() to cancel the timer's underlying delayed work. If the work callback (_brcms_timer) is already running, cancel_delayed_work() returns false without waiting, and brcms_free_timer() proceeds to kfree(t) while the callback still accesses t through container_of(). Add an explicit cancel_delayed_work_sync() after brcms_del_timer() to guarantee that any in-flight callback has completed before the timer structure is freed.
In the Linux kernel, the following vulnerability has been resolved: wifi: brcmsmac: fix UAF in brcms_free_timer() brcms_free_timer() calls brcms_del_timer() which uses the non-synchronous cancel_delayed_work() to cancel the timer's underlying delayed work. If the work callback (_brcms_timer) is already running, cancel_delayed_work() returns false without waiting, and brcms_free_timer() proceeds to kfree(t) while the callback still accesses t through container_of(). Add an explicit cancel_delayed_work_sync() after brcms_del_timer() to guarantee that any in-flight callback has completed before the timer structure is freed.
In the Linux kernel, the following vulnerability has been resolved: w ...
In the Linux kernel, the following vulnerability has been resolved: wifi: brcmsmac: fix UAF in brcms_free_timer() brcms_free_timer() calls brcms_del_timer() which uses the non-synchronous cancel_delayed_work() to cancel the timer's underlying delayed work. If the work callback (_brcms_timer) is already running, cancel_delayed_work() returns false without waiting, and brcms_free_timer() proceeds to kfree(t) while the callback still accesses t through container_of(). Add an explicit cancel_delayed_work_sync() after brcms_del_timer() to guarantee that any in-flight callback has completed before the timer structure is freed.
EPSS
4.7 Medium
CVSS3