Описание
In the Linux kernel, the following vulnerability has been resolved:
s390/boot: Avoid IPL parameter append past command line
A command line may occupy all but the terminating byte of
COMMAND_LINE_SIZE. In that case append_ipl_block_parm() passes a zero size
to the IPL parameter conversion helpers and points the destination one
byte past early_command_line. The helpers subtract one from the unsigned
size and write the converted parameter outside the command line buffer.
Convert the IPL parameter in the command line parsing buffer first. A
parameter beginning with '=' can then replace the existing command line
regardless of its length, while other parameters are appended only when
space remains.
A flaw was found in the Linux kernel's s390 boot code. This flaw can lead to a Denial of Service (DoS) through memory corruption during system startup. When the early boot command-line buffer is nearly full, appending Initial Program Load (IPL) parameters triggers an integer underflow, causing an out-of-bounds write outside the designated buffer. A user capable of specifying custom boot parameters can exploit this vulnerability during system initialization to crash the system.
Отчет
An out of bounds write can occur during s390 early boot when early_command_line occupies all available space except for its terminating byte. append_ipl_block_parm() then passes a zero destination size and a pointer beyond the command line buffer to an IPL parameter conversion helper. The helper subtracts one from the unsigned size, producing a very large effective bound and allowing converted IPL parameter data to overwrite adjacent boot memory. The demonstrated impact includes corruption of boot data, altered boot behavior, or failure to boot. The broader confidentiality and integrity impact depends on the affected memory layout and is not proven as a practical privilege escalation. For the CVSS the PR:H value is used because reliable triggering normally requires administrative control over the s390 boot command line or IPL parameter block. The issue is not directly network reachable and executes before normal userspace starts. Impact is at least denial of service and boot state corruption.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options don't 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 | 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 | Affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | 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 | Affected | ||
| Red Hat OpenShift Container Platform 5 | openshift/ose-rhel-coreos-9 | Affected |
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Дополнительная информация
Статус:
EPSS
6 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: s390/boot: Avoid IPL parameter append past command line A command line may occupy all but the terminating byte of COMMAND_LINE_SIZE. In that case append_ipl_block_parm() passes a zero size to the IPL parameter conversion helpers and points the destination one byte past early_command_line. The helpers subtract one from the unsigned size and write the converted parameter outside the command line buffer. Convert the IPL parameter in the command line parsing buffer first. A parameter beginning with '=' can then replace the existing command line regardless of its length, while other parameters are appended only when space remains.
In the Linux kernel, the following vulnerability has been resolved: s390/boot: Avoid IPL parameter append past command line A command line may occupy all but the terminating byte of COMMAND_LINE_SIZE. In that case append_ipl_block_parm() passes a zero size to the IPL parameter conversion helpers and points the destination one byte past early_command_line. The helpers subtract one from the unsigned size and write the converted parameter outside the command line buffer. Convert the IPL parameter in the command line parsing buffer first. A parameter beginning with '=' can then replace the existing command line regardless of its length, while other parameters are appended only when space remains.
In the Linux kernel, the following vulnerability has been resolved: s ...
In the Linux kernel, the following vulnerability has been resolved: s390/boot: Avoid IPL parameter append past command line A command line may occupy all but the terminating byte of COMMAND_LINE_SIZE. In that case append_ipl_block_parm() passes a zero size to the IPL parameter conversion helpers and points the destination one byte past early_command_line. The helpers subtract one from the unsigned size and write the converted parameter outside the command line buffer. Convert the IPL parameter in the command line parsing buffer first. A parameter beginning with '=' can then replace the existing command line regardless of its length, while other parameters are appended only when space remains.
EPSS
6 Medium
CVSS3