Описание
In the Linux kernel, the following vulnerability has been resolved:
slab: Avoid race on slab->obj_exts in alloc_slab_obj_exts
If two competing threads enter alloc_slab_obj_exts() and one of them
fails to allocate the object extension vector, it might override the
valid slab->obj_exts allocated by the other thread with
OBJEXTS_ALLOC_FAIL. This will cause the thread that lost this race and
expects a valid pointer to dereference a NULL pointer later on.
Update slab->obj_exts atomically using cmpxchg() to avoid
slab->obj_exts overrides by racing threads.
Thanks for Vlastimil and Suren's help with debugging.
A race condition was found in the Linux kernel's slab allocator. When two threads concurrently call alloc_slab_obj_exts() and one fails allocation, it may overwrite the other's valid obj_exts pointer with OBJEXTS_ALLOC_FAIL. The winning thread later dereferences this as a valid pointer, causing a null pointer dereference.
Отчет
This race exists in core memory allocation code but requires CONFIG_SLUB_DEBUG or CONFIG_MEMCG_KMEM enabled with specific concurrent allocation patterns. The fix uses cmpxchg for atomic updates.
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: slab: Avoid race on slab->obj_exts in alloc_slab_obj_exts If two competing threads enter alloc_slab_obj_exts() and one of them fails to allocate the object extension vector, it might override the valid slab->obj_exts allocated by the other thread with OBJEXTS_ALLOC_FAIL. This will cause the thread that lost this race and expects a valid pointer to dereference a NULL pointer later on. Update slab->obj_exts atomically using cmpxchg() to avoid slab->obj_exts overrides by racing threads. Thanks for Vlastimil and Suren's help with debugging.
In the Linux kernel, the following vulnerability has been resolved: slab: Avoid race on slab->obj_exts in alloc_slab_obj_exts If two competing threads enter alloc_slab_obj_exts() and one of them fails to allocate the object extension vector, it might override the valid slab->obj_exts allocated by the other thread with OBJEXTS_ALLOC_FAIL. This will cause the thread that lost this race and expects a valid pointer to dereference a NULL pointer later on. Update slab->obj_exts atomically using cmpxchg() to avoid slab->obj_exts overrides by racing threads. Thanks for Vlastimil and Suren's help with debugging.
In the Linux kernel, the following vulnerability has been resolved: s ...
In the Linux kernel, the following vulnerability has been resolved: slab: Avoid race on slab->obj_exts in alloc_slab_obj_exts If two competing threads enter alloc_slab_obj_exts() and one of them fails to allocate the object extension vector, it might override the valid slab->obj_exts allocated by the other thread with OBJEXTS_ALLOC_FAIL. This will cause the thread that lost this race and expects a valid pointer to dereference a NULL pointer later on. Update slab->obj_exts atomically using cmpxchg() to avoid slab->obj_exts overrides by racing threads. Thanks for Vlastimil and Suren's help with debugging.
ELSA-2026-50006: Unbreakable Enterprise kernel security update (IMPORTANT)
5.5 Medium
CVSS3