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CVE-2021-47218

Опубликовано: 10 апр. 2024
Источник: redhat
CVSS3: 4.4
EPSS Низкий

Описание

In the Linux kernel, the following vulnerability has been resolved: selinux: fix NULL-pointer dereference when hashtab allocation fails When the hash table slot array allocation fails in hashtab_init(), h->size is left initialized with a non-zero value, but the h->htable pointer is NULL. This may then cause a NULL pointer dereference, since the policydb code relies on the assumption that even after a failed hashtab_init(), hashtab_map() and hashtab_destroy() can be safely called on it. Yet, these detect an empty hashtab only by looking at the size. Fix this by making sure that hashtab_init() always leaves behind a valid empty hashtab when the allocation fails.

A vulnerability was found in the Linux kernel, related to SELinux. This issue occurs when a hash table allocation fails during the hashtab_init() function. When this failure happens, the system leaves the hash table (h->size) initialized with a non-zero value, but the h->htable pointer remains null. This can result in a null pointer dereference when SELinux's policy database tries to use the hash table, relying on the assumption that it is valid. This situation can cause system crashes or unexpected behavior.

Отчет

The fix for this issue ensures that even in the case of allocation failure, hashtab_init() leaves behind a valid empty hash table, preventing the null pointer dereference and improving the stability of SELinux in this context​

Затронутые пакеты

ПлатформаПакетСостояниеРекомендацияРелиз
Red Hat Enterprise Linux 6kernelOut of support scope
Red Hat Enterprise Linux 7kernelOut of support scope
Red Hat Enterprise Linux 7kernel-rtOut of support scope
Red Hat Enterprise Linux 8kernelAffected
Red Hat Enterprise Linux 8kernel-rtAffected
Red Hat Enterprise Linux 9kernelNot affected
Red Hat Enterprise Linux 9kernel-rtNot affected

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Дополнительная информация

Статус:

Moderate
Дефект:
CWE-476
https://bugzilla.redhat.com/show_bug.cgi?id=2274568kernel: selinux: fix NULL-pointer dereference when hashtab allocation fails

EPSS

Процентиль: 1%
0.00011
Низкий

4.4 Medium

CVSS3

Связанные уязвимости

CVSS3: 5.5
ubuntu
около 1 года назад

In the Linux kernel, the following vulnerability has been resolved: selinux: fix NULL-pointer dereference when hashtab allocation fails When the hash table slot array allocation fails in hashtab_init(), h->size is left initialized with a non-zero value, but the h->htable pointer is NULL. This may then cause a NULL pointer dereference, since the policydb code relies on the assumption that even after a failed hashtab_init(), hashtab_map() and hashtab_destroy() can be safely called on it. Yet, these detect an empty hashtab only by looking at the size. Fix this by making sure that hashtab_init() always leaves behind a valid empty hashtab when the allocation fails.

CVSS3: 5.5
nvd
около 1 года назад

In the Linux kernel, the following vulnerability has been resolved: selinux: fix NULL-pointer dereference when hashtab allocation fails When the hash table slot array allocation fails in hashtab_init(), h->size is left initialized with a non-zero value, but the h->htable pointer is NULL. This may then cause a NULL pointer dereference, since the policydb code relies on the assumption that even after a failed hashtab_init(), hashtab_map() and hashtab_destroy() can be safely called on it. Yet, these detect an empty hashtab only by looking at the size. Fix this by making sure that hashtab_init() always leaves behind a valid empty hashtab when the allocation fails.

CVSS3: 5.5
debian
около 1 года назад

In the Linux kernel, the following vulnerability has been resolved: s ...

CVSS3: 5.5
github
около 1 года назад

In the Linux kernel, the following vulnerability has been resolved: selinux: fix NULL-pointer dereference when hashtab allocation fails When the hash table slot array allocation fails in hashtab_init(), h->size is left initialized with a non-zero value, but the h->htable pointer is NULL. This may then cause a NULL pointer dereference, since the policydb code relies on the assumption that even after a failed hashtab_init(), hashtab_map() and hashtab_destroy() can be safely called on it. Yet, these detect an empty hashtab only by looking at the size. Fix this by making sure that hashtab_init() always leaves behind a valid empty hashtab when the allocation fails.

CVSS3: 5.5
fstec
больше 3 лет назад

Уязвимость компонента selinux ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании

EPSS

Процентиль: 1%
0.00011
Низкий

4.4 Medium

CVSS3