Linux Kernel kexec SMT Enablement Fix (CVE-2025-71119)
CVE-2025-71119 Published on January 14, 2026
powerpc/kexec: Enable SMT before waking offline CPUs
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.
Products Associated with CVE-2025-71119
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Affected Versions
Linux:- Version 482fa21635c8832db022cd2d649db26b8e6170ac and below 7cccd82a0e4aad192fd74fc60e61ed9aed5857a3 is affected.
- Version 38253464bc821d6de6bba81bb1412ebb36f6cbd1 and below d790ef0c4819424ee0c2f448c0a8154c5ca369d1 is affected.
- Version 38253464bc821d6de6bba81bb1412ebb36f6cbd1 and below f0c0a681ffb77b8c5290c88c02d968199663939b is affected.
- Version 38253464bc821d6de6bba81bb1412ebb36f6cbd1 and below 0d5c9e901ad40bd39b38e119c0454b52d7663930 is affected.
- Version 38253464bc821d6de6bba81bb1412ebb36f6cbd1 and below c2296a1e42418556efbeb5636c4fa6aa6106713a is affected.
- Version 15141adf85b14a7cff7abba1cb983f0bf17e3b36 is affected.
- Version 6.6 is affected.
- Before 6.6 is unaffected.
- Version 6.1.160, <= 6.1.* is unaffected.
- Version 6.6.120, <= 6.6.* is unaffected.
- Version 6.12.64, <= 6.12.* is unaffected.
- Version 6.18.3, <= 6.18.* is unaffected.
- Version 6.19, <= * is unaffected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.