Описание
In the Linux kernel, the following vulnerability has been resolved:
fsverity: RCU-delay the freeing of struct fsverity_info
__fsverity_get_info() calls rhashtable_lookup_fast(), which just uses
rcu_read_lock() and doesn't directly synchronize with
fsverity_remove_info().
For the same inode this isn't a problem: its fsverity_info is removed
only at inode eviction time or upon failure to enable verity, when the
inode no longer needs its fsverity_info and it will no longer be
accessed via that inode.
However, this is broken and can cause a use-after-free for concurrent
__fsverity_get_info() for different inodes. Those rely on following
fsverity_info::rhash_head in the rhashtable under rcu_read_lock() only.
They also use fsverity_info::inode to do the key comparison.
Fix this by RCU-delaying the freeing of 'struct fsverity_info' after
it's been removed from the rhashtable.
A flaw was found in the Linux kernel's fsverity subsystem. A lack of proper synchronization when removing file verification structures allows concurrent lookup operations to access memory after it has been freed. A local user could exploit this vulnerability by triggering simultaneous file operations to cause a system crash, resulting in a denial of service (DoS), or potentially execute arbitrary code.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Not affected | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| 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: fsverity: RCU-delay the freeing of struct fsverity_info __fsverity_get_info() calls rhashtable_lookup_fast(), which just uses rcu_read_lock() and doesn't directly synchronize with fsverity_remove_info(). For the same inode this isn't a problem: its fsverity_info is removed only at inode eviction time or upon failure to enable verity, when the inode no longer needs its fsverity_info and it will no longer be accessed via that inode. However, this is broken and can cause a use-after-free for concurrent __fsverity_get_info() for *different* inodes. Those rely on following fsverity_info::rhash_head in the rhashtable under rcu_read_lock() only. They also use fsverity_info::inode to do the key comparison. Fix this by RCU-delaying the freeing of 'struct fsverity_info' after it's been removed from the rhashtable.
In the Linux kernel, the following vulnerability has been resolved: fsverity: RCU-delay the freeing of struct fsverity_info __fsverity_get_info() calls rhashtable_lookup_fast(), which just uses rcu_read_lock() and doesn't directly synchronize with fsverity_remove_info(). For the same inode this isn't a problem: its fsverity_info is removed only at inode eviction time or upon failure to enable verity, when the inode no longer needs its fsverity_info and it will no longer be accessed via that inode. However, this is broken and can cause a use-after-free for concurrent __fsverity_get_info() for *different* inodes. Those rely on following fsverity_info::rhash_head in the rhashtable under rcu_read_lock() only. They also use fsverity_info::inode to do the key comparison. Fix this by RCU-delaying the freeing of 'struct fsverity_info' after it's been removed from the rhashtable.
In the Linux kernel, the following vulnerability has been resolved: f ...
In the Linux kernel, the following vulnerability has been resolved: fsverity: RCU-delay the freeing of struct fsverity_info __fsverity_get_info() calls rhashtable_lookup_fast(), which just uses rcu_read_lock() and doesn't directly synchronize with fsverity_remove_info(). For the same inode this isn't a problem: its fsverity_info is removed only at inode eviction time or upon failure to enable verity, when the inode no longer needs its fsverity_info and it will no longer be accessed via that inode. However, this is broken and can cause a use-after-free for concurrent __fsverity_get_info() for *different* inodes. Those rely on following fsverity_info::rhash_head in the rhashtable under rcu_read_lock() only. They also use fsverity_info::inode to do the key comparison. Fix this by RCU-delaying the freeing of 'struct fsverity_info' after it's been removed from the rhashtable.
EPSS
5.5 Medium
CVSS3