Описание
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: reject non-inline dinodes with i_size and zero i_clusters
On a volume mounted without OCFS2_FEATURE_INCOMPAT_SPARSE_ALLOC, a
non-inline regular file with non-zero i_size and zero i_clusters is
structurally malformed: the extent map declares no allocated clusters yet
the size header claims content exists. Keep rejecting that shape, but
express it through a shared predicate so the same invariant is available
to normal inode reads and online filecheck.
The same zero-cluster shape is also malformed for non-inline directories.
ocfs2 directory growth allocates backing storage before advancing i_size,
and ocfs2_dir_foreach_blk_el() later walks until ctx->pos reaches
i_size_read(inode). A forged directory dinode with a huge i_size and no
clusters would repeatedly fail on holes while advancing through the
claimed size.
Sparse regular files remain exempt: on sparse-alloc volumes, truncate can
legitimately grow i_size without allocating clusters. System inodes and
inline-data dinodes also retain their separate storage rules.
Mirror the check in ocfs2_filecheck_validate_inode_block() as well.
filecheck reports through its own error namespace, so malformed
size/cluster state is logged as a filecheck invalid-inode result rather
than via ocfs2_error(), but it must not proceed into
ocfs2_populate_inode().
A flaw was found in the OCFS2 file system within the Linux kernel. This vulnerability occurs when processing specially crafted file system metadata, specifically non-inline dinodes that report a non-zero file size but zero allocated clusters. An attacker could potentially create a malformed file system structure that, when processed, leads to repeated failures and system instability, resulting in a denial of service.
Отчет
A moderate severity denial of service flaw was found in the Linux kernel's OCFS2 file system. When processing specially crafted file system metadata, specifically a non-inline dinode that reports a non-zero file size (i_size) while having zero allocated clusters (i_clusters), the kernel could repeatedly fail while advancing through the claimed size, for example when iterating a forged directory dinode with a huge i_size and no backing clusters, resulting in system instability and a denial of service. Exploiting this flaw requires local access to a system with a mounted OCFS2 file system and privileges sufficient to introduce malformed file system metadata (Red Hat CVSS 5.5, AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). The Red Hat Enterprise Linux and Red Hat In-Vehicle OS kernel packages tracked for this flaw are not affected because the vulnerable code is not present in the shipped kernels.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options do not 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 | 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 |
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Дополнительная информация
Статус:
EPSS
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: ocfs2: reject non-inline dinodes with i_size and zero i_clusters On a volume mounted without OCFS2_FEATURE_INCOMPAT_SPARSE_ALLOC, a non-inline regular file with non-zero i_size and zero i_clusters is structurally malformed: the extent map declares no allocated clusters yet the size header claims content exists. Keep rejecting that shape, but express it through a shared predicate so the same invariant is available to normal inode reads and online filecheck. The same zero-cluster shape is also malformed for non-inline directories. ocfs2 directory growth allocates backing storage before advancing i_size, and ocfs2_dir_foreach_blk_el() later walks until ctx->pos reaches i_size_read(inode). A forged directory dinode with a huge i_size and no clusters would repeatedly fail on holes while advancing through the claimed size. Sparse regular files remain exempt: on sparse-alloc volumes, truncate can legitimately grow i_size...
In the Linux kernel, the following vulnerability has been resolved: ocfs2: reject non-inline dinodes with i_size and zero i_clusters On a volume mounted without OCFS2_FEATURE_INCOMPAT_SPARSE_ALLOC, a non-inline regular file with non-zero i_size and zero i_clusters is structurally malformed: the extent map declares no allocated clusters yet the size header claims content exists. Keep rejecting that shape, but express it through a shared predicate so the same invariant is available to normal inode reads and online filecheck. The same zero-cluster shape is also malformed for non-inline directories. ocfs2 directory growth allocates backing storage before advancing i_size, and ocfs2_dir_foreach_blk_el() later walks until ctx->pos reaches i_size_read(inode). A forged directory dinode with a huge i_size and no clusters would repeatedly fail on holes while advancing through the claimed size. Sparse regular files remain exempt: on sparse-alloc volumes, truncate can legitimately grow i_si
In the Linux kernel, the following vulnerability has been resolved: o ...
EPSS
5.5 Medium
CVSS3