Описание
System software utilizing Lazy FP state restore technique on systems using Intel Core-based microprocessors may potentially allow a local process to infer data from another process through a speculative execution side channel.
A Floating Point Unit (FPU) state information leakage flaw was found in the way the Linux kernel saved and restored the FPU state during task switch. Linux kernels that follow the "Lazy FPU Restore" scheme are vulnerable to the FPU state information leakage issue. An unprivileged local attacker could use this flaw to read FPU state bits by conducting targeted cache side-channel attacks, similar to the Meltdown vulnerability disclosed earlier this year.
Отчет
This issue affects the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 5, 6, 7, and Red Hat Enterprise MRG 2. Future kernel updates for Red Hat Enterprise Linux 6, 7, and Red Hat Enterprise MRG 2 may address this issue. Red Hat Enterprise Linux 5 is now in Production 3 Phase of the support and maintenance life cycle. This has been rated as having Moderate security impact and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.
Меры по смягчению последствий
RHEL-7 will automatically default to (safe) “eager” floating point register restore on Sandy Bridge and newer Intel processors. AMD processors are not affected. You can mitigate this issue on older processors by booting the kernel with the 'eagerfpu=on' parameter to enable eager FPU restore mode. In this mode FPU state is saved and restored for every task/context switch regardless of whether the current process invokes FPU instructions or not. The parameter does not affect performance negatively, and can be applied with no adverse effects to processors that are not affected.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 5 | kernel | Out of support scope | ||
| Red Hat Enterprise Linux 7 | kernel-alt | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 6 | kernel | Fixed | RHSA-2018:2164 | 10.07.2018 |
| Red Hat Enterprise Linux 7 | kernel-rt | Fixed | RHSA-2018:1944 | 19.06.2018 |
| Red Hat Enterprise Linux 7 | kernel | Fixed | RHSA-2018:1852 | 14.06.2018 |
| Red Hat Enterprise Linux 7.4 Extended Update Support | kernel | Fixed | RHSA-2019:1170 | 14.05.2019 |
| Red Hat Enterprise MRG 2 | kernel-rt | Fixed | RHSA-2018:2165 | 10.07.2018 |
| Red Hat Enterprise MRG 2 | kernel-rt | Fixed | RHSA-2019:1190 | 14.05.2019 |
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Дополнительная информация
Статус:
5.6 Medium
CVSS3
Связанные уязвимости
System software utilizing Lazy FP state restore technique on systems using Intel Core-based microprocessors may potentially allow a local process to infer data from another process through a speculative execution side channel.
System software utilizing Lazy FP state restore technique on systems using Intel Core-based microprocessors may potentially allow a local process to infer data from another process through a speculative execution side channel.
System software utilizing Lazy FP state restore technique on systems u ...
Security update for the Linux Kernel (Live Patch 11 for SLE 12 SP3)
Security update for the Linux Kernel (Live Patch 4 for SLE 12 SP3)
5.6 Medium
CVSS3