Описание
In the Linux kernel, the following vulnerability has been resolved:
evm: terminate and bound the evm_xattrs read buffer
evm_read_xattrs() allocates size + 1 bytes, fills them from the list of
enabled xattrs, and then passes strlen(temp) to
simple_read_from_buffer(). When no configured xattrs are enabled, the
fill loop stores nothing and temp[0] remains uninitialized, so strlen()
reads beyond initialized memory.
Explicitly terminate the buffer after allocation, use snprintf() for
each formatted line, and pass the accumulated length, without risk of
truncation, to simple_read_from_buffer().
A flaw was found in the Linux kernel's Extended Verification Module (EVM). The evm_read_xattrs() function, when processing extended attributes, fails to properly initialize a buffer. This can lead to an out-of-bounds read when no extended attributes are configured, potentially allowing an attacker to cause a denial of service (DoS) or disclose sensitive information.
Отчет
A moderate out-of-bounds read flaw was found in the Linux kernel's Extended Verification Module (EVM). The evm_read_xattrs() function, which serves the list of enabled EVM extended attributes through securityfs, allocates a buffer without initializing it and passes strlen() of that buffer to simple_read_from_buffer(). When no EVM extended attributes are configured, the fill loop stores nothing and the buffer remains uninitialized, so strlen() reads beyond initialized memory; a local user able to read the EVM securityfs xattrs file could use this to disclose kernel memory contents or cause a denial of service. Red Hat rates this flaw Moderate (CVSS 5.5, AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H); exploitation requires local access. Red Hat Enterprise Linux 8, 9, and 10 (kernel and kernel-rt) and Red Hat In-Vehicle OS 2 are affected. Red Hat Enterprise Linux 6 and 7 Extended Lifecycle Support are not affected because the vulnerable code is not present in those releases. Fixes for the affected streams are currently deferred; the residual risk until a fix is delivered is limited because triggering the flaw requires local access to the EVM securityfs interface and the primary impact is availability.
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 | Fix deferred | ||
| 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 | Fix deferred | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Fix deferred | ||
| Red Hat Enterprise Linux 9 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Fix deferred |
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Дополнительная информация
Статус:
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: evm: terminate and bound the evm_xattrs read buffer evm_read_xattrs() allocates size + 1 bytes, fills them from the list of enabled xattrs, and then passes strlen(temp) to simple_read_from_buffer(). When no configured xattrs are enabled, the fill loop stores nothing and temp[0] remains uninitialized, so strlen() reads beyond initialized memory. Explicitly terminate the buffer after allocation, use snprintf() for each formatted line, and pass the accumulated length, without risk of truncation, to simple_read_from_buffer().
In the Linux kernel, the following vulnerability has been resolved: evm: terminate and bound the evm_xattrs read buffer evm_read_xattrs() allocates size + 1 bytes, fills them from the list of enabled xattrs, and then passes strlen(temp) to simple_read_from_buffer(). When no configured xattrs are enabled, the fill loop stores nothing and temp[0] remains uninitialized, so strlen() reads beyond initialized memory. Explicitly terminate the buffer after allocation, use snprintf() for each formatted line, and pass the accumulated length, without risk of truncation, to simple_read_from_buffer().
In the Linux kernel, the following vulnerability has been resolved: e ...
5.5 Medium
CVSS3