Описание
In the Linux kernel, the following vulnerability has been resolved:
nfsd: fix possible badness in FREE_STATEID
When multiple FREE_STATEIDs are sent for the same delegation stateid,
it can lead to a possible either use-after-free or counter refcount
underflow errors.
In nfsd4_free_stateid() under the client lock we find a delegation
stateid, however the code drops the lock before calling nfs4_put_stid(),
that allows another FREE_STATE to find the stateid again. The first one
will proceed to then free the stateid which leads to either
use-after-free or decrementing already zeroed counter.
A flaw was found in the Linux kernel's nfsd component. When multiple FREE_STATEIDs are sent for the same delegation stateid, a race condition can occur in the nfsd4_free_stateid() function. This allows the stateid to be accessed again after it has been prematurely released, leading to a use-after-free condition or a counter refcount underflow. This memory corruption vulnerability can result in system instability or a denial of service (DoS).
Меры по смягчению последствий
To mitigate this vulnerability, restrict network access to the NFS service to only trusted clients or networks. This can be achieved by configuring firewall rules.
For systems using firewalld:
firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="2049" protocol="tcp" accept'
firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="2049" protocol="udp" accept'
firewall-cmd --reload
Replace <TRUSTED_NETWORK> with the IP address or network range of your trusted NFS clients. This action may impact legitimate NFS clients if not configured correctly. Reloading the firewall service is required for changes to take effect.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 6 | kernel | Out of support scope | ||
| Red Hat Enterprise Linux 7 | kernel | Out of support scope | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Out of support scope | ||
| 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 |
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Дополнительная информация
Статус:
EPSS
7.8 High
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix possible badness in FREE_STATEID When multiple FREE_STATEIDs are sent for the same delegation stateid, it can lead to a possible either use-after-free or counter refcount underflow errors. In nfsd4_free_stateid() under the client lock we find a delegation stateid, however the code drops the lock before calling nfs4_put_stid(), that allows another FREE_STATE to find the stateid again. The first one will proceed to then free the stateid which leads to either use-after-free or decrementing already zeroed counter.
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix possible badness in FREE_STATEID When multiple FREE_STATEIDs are sent for the same delegation stateid, it can lead to a possible either use-after-free or counter refcount underflow errors. In nfsd4_free_stateid() under the client lock we find a delegation stateid, however the code drops the lock before calling nfs4_put_stid(), that allows another FREE_STATE to find the stateid again. The first one will proceed to then free the stateid which leads to either use-after-free or decrementing already zeroed counter.
In the Linux kernel, the following vulnerability has been resolved: n ...
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix possible badness in FREE_STATEID When multiple FREE_STATEIDs are sent for the same delegation stateid, it can lead to a possible either use-after-free or counter refcount underflow errors. In nfsd4_free_stateid() under the client lock we find a delegation stateid, however the code drops the lock before calling nfs4_put_stid(), that allows another FREE_STATE to find the stateid again. The first one will proceed to then free the stateid which leads to either use-after-free or decrementing already zeroed counter.
Уязвимость функции nfsd4_free_stateid() модуля fs/nfsd/nfs4state.c ядра операционной системы Linux, позволяющая нарушителю оказать воздействие на конфиденциальность, целостность и доступность защищаемой информации
EPSS
7.8 High
CVSS3