CVE-2025-38169

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> arm64/fpsimd: Avoid clobbering kernel FPSIMD state with SMSTOP<br /> <br /> On system with SME, a thread&amp;#39;s kernel FPSIMD state may be erroneously<br /> clobbered during a context switch immediately after that state is<br /> restored. Systems without SME are unaffected.<br /> <br /> If the CPU happens to be in streaming SVE mode before a context switch<br /> to a thread with kernel FPSIMD state, fpsimd_thread_switch() will<br /> restore the kernel FPSIMD state using fpsimd_load_kernel_state() while<br /> the CPU is still in streaming SVE mode. When fpsimd_thread_switch()<br /> subsequently calls fpsimd_flush_cpu_state(), this will execute an<br /> SMSTOP, causing an exit from streaming SVE mode. The exit from<br /> streaming SVE mode will cause the hardware to reset a number of<br /> FPSIMD/SVE/SME registers, clobbering the FPSIMD state.<br /> <br /> Fix this by calling fpsimd_flush_cpu_state() before restoring the kernel<br /> FPSIMD state.