Описание
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix NULL h_transaction deref in ocfs2_assure_trans_credits
[BUG]
A direct write over unwritten extents can panic the kernel in
ocfs2_assure_trans_credits() when the journal aborts during DIO
completion. The crash is a general protection fault from a NULL pointer
dereference.
[CAUSE]
ocfs2_dio_end_io_write() loops over a direct write's unwritten extents,
marking each written under a single journal handle. If the journal
aborts (for example after an I/O error) while the extent tree is being
updated, the handle is left aborted with its transaction pointer
cleared. The extent merge treats that failure as not critical and
reports success, so the loop keeps using the handle.
ocfs2_assure_trans_credits() reads the handle's remaining credits
without first checking whether the handle is aborted, and that read
dereferences the cleared transaction pointer.
[FIX]
A journal abort is recorded in the handle itself, so callers are
expected to test the handle rather than rely on a returned error.
Make ocfs2_assure_trans_credits() do that, as the other ocfs2 journal
helpers already do, and return -EROFS when the handle is aborted.
A flaw was found in the Linux kernel's OCFS2 component. A local user with write access to an OCFS2 filesystem could trigger a kernel panic by performing a direct write over unwritten extents. This occurs when the journal aborts during Direct I/O (DIO) completion, leading to a NULL pointer dereference in the ocfs2_assure_trans_credits function. Successful exploitation results in a system crash, causing a Denial of Service (DoS).
Отчет
A moderate impact flaw was found in the Linux kernel's OCFS2 file system. A local user with write access to an OCFS2 file system could cause a kernel panic (denial of service) by performing a direct write over unwritten extents: when the journal aborts during Direct I/O (DIO) completion, for example after an I/O error, the loop in ocfs2_dio_end_io_write() keeps using the aborted journal handle, and ocfs2_assure_trans_credits() reads the handle's remaining transaction credits without first checking whether the handle is aborted, dereferencing the cleared (NULL) transaction pointer and causing a general protection fault and system crash. All Red Hat Enterprise Linux and Red Hat In-Vehicle OS kernel streams listed in this flaw are not affected because the vulnerable code is not present in the shipped kernel versions, so no update is required for Red Hat products.
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:
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix NULL h_transaction deref in ocfs2_assure_trans_credits [BUG] A direct write over unwritten extents can panic the kernel in ocfs2_assure_trans_credits() when the journal aborts during DIO completion. The crash is a general protection fault from a NULL pointer dereference. [CAUSE] ocfs2_dio_end_io_write() loops over a direct write's unwritten extents, marking each written under a single journal handle. If the journal aborts (for example after an I/O error) while the extent tree is being updated, the handle is left aborted with its transaction pointer cleared. The extent merge treats that failure as not critical and reports success, so the loop keeps using the handle. ocfs2_assure_trans_credits() reads the handle's remaining credits without first checking whether the handle is aborted, and that read dereferences the cleared transaction pointer. [FIX] A journal abort is recorded in the handle itself, so calle...
In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix NULL h_transaction deref in ocfs2_assure_trans_credits [BUG] A direct write over unwritten extents can panic the kernel in ocfs2_assure_trans_credits() when the journal aborts during DIO completion. The crash is a general protection fault from a NULL pointer dereference. [CAUSE] ocfs2_dio_end_io_write() loops over a direct write's unwritten extents, marking each written under a single journal handle. If the journal aborts (for example after an I/O error) while the extent tree is being updated, the handle is left aborted with its transaction pointer cleared. The extent merge treats that failure as not critical and reports success, so the loop keeps using the handle. ocfs2_assure_trans_credits() reads the handle's remaining credits without first checking whether the handle is aborted, and that read dereferences the cleared transaction pointer. [FIX] A journal abort is recorded in the handle itself, so call
In the Linux kernel, the following vulnerability has been resolved: o ...
5.5 Medium
CVSS3