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CVE-2025-38169

In the Linux kernel, the following vulnerability has been resolved: arm64/fpsimd: Avoid clobbering kernel FPSIMD state with SMSTOP On system with SME, a thread's kerne…

Published Jul 3, 2025 · updated Oct 15, 2026 · linux linux kernel

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

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Jul 3, 2025 · NIST NVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: arm64/fpsimd: Avoid clobbering kernel FPSIMD state with SMSTOP On system with SME, a thread's kernel FPSIMD state may be erroneously clobbered during a context switch immediately after that state is restored. Systems without SME are unaffected. If the CPU happens to be in streaming SVE mode before a context switch to a thread with

  2. Oct 15, 2026 · NIST NVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: arm64/fpsimd: Avoid clobbering kernel FPSIMD state with SMSTOP On system with SME, a thread's kernel FPSIMD state may be erroneously clobbered during a context switch immediately after that state is restored. Systems without SME are unaffected. If the CPU happens to be in streaming SVE mode before a context switch to a thread with

Affected

  • cpe linux/linux kernelversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2025-38169

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2025-38169

    In the Linux kernel, the following vulnerability has been resolved: arm64/fpsimd: Avoid clobbering kernel FPSIMD state with SMSTOP On system with SME, a thread's kernel FPSIMD state may be erroneously clobbered during a context switch immediately after that state is restored. S

    nvd.nist.gov

References