Описание
In the Linux kernel, the following vulnerability has been resolved:
powerpc/kexec: Enable SMT before waking offline CPUs
If SMT is disabled or a partial SMT state is enabled, when a new kernel
image is loaded for kexec, on reboot the following warning is observed:
kexec: Waking offline cpu 228.
WARNING: CPU: 0 PID: 9062 at arch/powerpc/kexec/core_64.c:223 kexec_prepare_cpus+0x1b0/0x1bc
[snip]
NIP kexec_prepare_cpus+0x1b0/0x1bc
LR kexec_prepare_cpus+0x1a0/0x1bc
Call Trace:
kexec_prepare_cpus+0x1a0/0x1bc (unreliable)
default_machine_kexec+0x160/0x19c
machine_kexec+0x80/0x88
kernel_kexec+0xd0/0x118
__do_sys_reboot+0x210/0x2c4
system_call_exception+0x124/0x320
system_call_vectored_common+0x15c/0x2ec
This occurs as add_cpu() fails due to cpu_bootable() returning false for
CPUs that fail the cpu_smt_thread_allowed() check or non primary
threads if SMT is disabled.
Fix the issue by enabling SMT and resetting the number of SMT threads to
the number of threads per core, before attempting to wake up all present
CPUs.
A warning condition was found in the Linux kernel's PowerPC kexec implementation. When SMT (Simultaneous Multi-Threading) is disabled or partially enabled, attempting to kexec into a new kernel triggers warnings because the kexec code tries to wake offline CPUs that fail the cpu_smt_thread_allowed() check. The add_cpu() call fails for non-primary threads when SMT is disabled, causing kernel warnings during the reboot process.
Отчет
This issue affects PowerPC systems using kexec when SMT is not fully enabled. The warning occurs during the kexec reboot sequence but does not prevent the kexec from completing. The impact is limited to kernel warnings in the log rather than a functional failure. This primarily affects enterprise PowerPC servers with many CPU cores.
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 | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel | Affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Affected |
Показывать по
Дополнительная информация
Статус:
EPSS
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: powerpc/kexec: Enable SMT before waking offline CPUs If SMT is disabled or a partial SMT state is enabled, when a new kernel image is loaded for kexec, on reboot the following warning is observed: kexec: Waking offline cpu 228. WARNING: CPU: 0 PID: 9062 at arch/powerpc/kexec/core_64.c:223 kexec_prepare_cpus+0x1b0/0x1bc [snip] NIP kexec_prepare_cpus+0x1b0/0x1bc LR kexec_prepare_cpus+0x1a0/0x1bc Call Trace: kexec_prepare_cpus+0x1a0/0x1bc (unreliable) default_machine_kexec+0x160/0x19c machine_kexec+0x80/0x88 kernel_kexec+0xd0/0x118 __do_sys_reboot+0x210/0x2c4 system_call_exception+0x124/0x320 system_call_vectored_common+0x15c/0x2ec This occurs as add_cpu() fails due to cpu_bootable() returning false for CPUs that fail the cpu_smt_thread_allowed() check or non primary threads if SMT is disabled. Fix the issue by enabling SMT and resetting the number of SMT threads to the number of threads per core, before attempting to...
In the Linux kernel, the following vulnerability has been resolved: powerpc/kexec: Enable SMT before waking offline CPUs If SMT is disabled or a partial SMT state is enabled, when a new kernel image is loaded for kexec, on reboot the following warning is observed: kexec: Waking offline cpu 228. WARNING: CPU: 0 PID: 9062 at arch/powerpc/kexec/core_64.c:223 kexec_prepare_cpus+0x1b0/0x1bc [snip] NIP kexec_prepare_cpus+0x1b0/0x1bc LR kexec_prepare_cpus+0x1a0/0x1bc Call Trace: kexec_prepare_cpus+0x1a0/0x1bc (unreliable) default_machine_kexec+0x160/0x19c machine_kexec+0x80/0x88 kernel_kexec+0xd0/0x118 __do_sys_reboot+0x210/0x2c4 system_call_exception+0x124/0x320 system_call_vectored_common+0x15c/0x2ec This occurs as add_cpu() fails due to cpu_bootable() returning false for CPUs that fail the cpu_smt_thread_allowed() check or non primary threads if SMT is disabled. Fix the issue by enabling SMT and resetting the number of SMT threads to the number of threads per core, b
In the Linux kernel, the following vulnerability has been resolved: p ...
In the Linux kernel, the following vulnerability has been resolved: powerpc/kexec: Enable SMT before waking offline CPUs If SMT is disabled or a partial SMT state is enabled, when a new kernel image is loaded for kexec, on reboot the following warning is observed: kexec: Waking offline cpu 228. WARNING: CPU: 0 PID: 9062 at arch/powerpc/kexec/core_64.c:223 kexec_prepare_cpus+0x1b0/0x1bc [snip] NIP kexec_prepare_cpus+0x1b0/0x1bc LR kexec_prepare_cpus+0x1a0/0x1bc Call Trace: kexec_prepare_cpus+0x1a0/0x1bc (unreliable) default_machine_kexec+0x160/0x19c machine_kexec+0x80/0x88 kernel_kexec+0xd0/0x118 __do_sys_reboot+0x210/0x2c4 system_call_exception+0x124/0x320 system_call_vectored_common+0x15c/0x2ec This occurs as add_cpu() fails due to cpu_bootable() returning false for CPUs that fail the cpu_smt_thread_allowed() check or non primary threads if SMT is disabled. Fix the issue by enabling SMT and resetting the number of SMT threads to the number of threads per core...
EPSS
5.5 Medium
CVSS3