{"id":"CVE-2025-38169","summary":"arm64/fpsimd: Avoid clobbering kernel FPSIMD state with SMSTOP","details":"In the Linux kernel, the following vulnerability has been resolved:\n\narm64/fpsimd: Avoid clobbering kernel FPSIMD state with SMSTOP\n\nOn system with SME, a thread's kernel FPSIMD state may be erroneously\nclobbered during a context switch immediately after that state is\nrestored. Systems without SME are unaffected.\n\nIf the CPU happens to be in streaming SVE mode before a context switch\nto a thread with kernel FPSIMD state, fpsimd_thread_switch() will\nrestore the kernel FPSIMD state using fpsimd_load_kernel_state() while\nthe CPU is still in streaming SVE mode. When fpsimd_thread_switch()\nsubsequently calls fpsimd_flush_cpu_state(), this will execute an\nSMSTOP, causing an exit from streaming SVE mode. The exit from\nstreaming SVE mode will cause the hardware to reset a number of\nFPSIMD/SVE/SME registers, clobbering the FPSIMD state.\n\nFix this by calling fpsimd_flush_cpu_state() before restoring the kernel\nFPSIMD state.","modified":"2026-03-20T12:42:43.164848Z","published":"2025-07-03T08:36:08.393Z","related":["SUSE-SU-2025:21074-1","SUSE-SU-2025:21139-1","SUSE-SU-2025:21179-1","openSUSE-SU-2025:20081-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/38xxx/CVE-2025-38169.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/01098d893fa8a6edb2b56e178b798e3e6b674f02"},{"type":"WEB","url":"https://git.kernel.org/stable/c/55d52af498daea75aa03ba9b7e444c8ae495ac20"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a305821f597ec943849d3e53924adb88c61ed682"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/38xxx/CVE-2025-38169.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-38169"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"e92bee9f861b466c676f0200be3e46af7bc4ac6b"},{"fixed":"55d52af498daea75aa03ba9b7e444c8ae495ac20"},{"fixed":"a305821f597ec943849d3e53924adb88c61ed682"},{"fixed":"01098d893fa8a6edb2b56e178b798e3e6b674f02"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0"},{"last_affected":"e003c485ac82a9f8de4204912ed059ac6dd4257c"},{"last_affected":"25b90cd122d546823da90b916f7c3289dfe83a99"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-38169.json"}}],"schema_version":"1.7.5"}