ghsa-m2xh-87px-jgff
Vulnerability from github
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.
{
"affected": [],
"aliases": [
"CVE-2025-38169"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-07-03T09:15:32Z",
"severity": null
},
"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\u0027s 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.",
"id": "GHSA-m2xh-87px-jgff",
"modified": "2025-07-03T09:30:35Z",
"published": "2025-07-03T09:30:35Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-38169"
},
{
"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"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
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