CVE-2025-71119

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> powerpc/kexec: Enable SMT before waking offline CPUs<br /> <br /> If SMT is disabled or a partial SMT state is enabled, when a new kernel<br /> image is loaded for kexec, on reboot the following warning is observed:<br /> <br /> kexec: Waking offline cpu 228.<br /> WARNING: CPU: 0 PID: 9062 at arch/powerpc/kexec/core_64.c:223 kexec_prepare_cpus+0x1b0/0x1bc<br /> [snip]<br /> NIP kexec_prepare_cpus+0x1b0/0x1bc<br /> LR kexec_prepare_cpus+0x1a0/0x1bc<br /> Call Trace:<br /> kexec_prepare_cpus+0x1a0/0x1bc (unreliable)<br /> default_machine_kexec+0x160/0x19c<br /> machine_kexec+0x80/0x88<br /> kernel_kexec+0xd0/0x118<br /> __do_sys_reboot+0x210/0x2c4<br /> system_call_exception+0x124/0x320<br /> system_call_vectored_common+0x15c/0x2ec<br /> <br /> This occurs as add_cpu() fails due to cpu_bootable() returning false for<br /> CPUs that fail the cpu_smt_thread_allowed() check or non primary<br /> threads if SMT is disabled.<br /> <br /> Fix the issue by enabling SMT and resetting the number of SMT threads to<br /> the number of threads per core, before attempting to wake up all present<br /> CPUs.