arm64/fpsimd: Avoid clobbering kernel FPSIMD state with SMSTOP
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
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| Linux | Linux | affected |
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Configuration 1 [-]
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No data.
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| Linux | Linux Kernel | — |
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EUVD |
EUVD-2025-19775 | 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. |
Ubuntu USN |
USN-7769-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7769-2 | Linux kernel (Real-time) vulnerabilities |
Ubuntu USN |
USN-7769-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7770-1 | Linux kernel (Azure) vulnerabilities |
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USN-7771-1 | Linux kernel (OEM) vulnerabilities |
Ubuntu USN |
USN-7789-1 | Linux kernel (Oracle) vulnerabilities |
Ubuntu USN |
USN-7789-2 | Linux kernel (Raspberry Pi) vulnerabilities |
Ubuntu USN |
USN-8028-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8028-2 | Linux kernel (Real-time) vulnerabilities |
Ubuntu USN |
USN-8031-1 | Linux kernel (GCP) vulnerabilities |
Ubuntu USN |
USN-8028-3 | Linux kernel (Real-time) vulnerabilities |
Ubuntu USN |
USN-8028-4 | Linux kernel (FIPS) vulnerabilities |
Ubuntu USN |
USN-8028-5 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8031-2 | Linux kernel (GCP FIPS) vulnerabilities |
Ubuntu USN |
USN-8028-6 | Linux kernel (HWE) vulnerabilities |
Ubuntu USN |
USN-8031-3 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-8052-1 | Linux kernel (Low Latency) vulnerabilities |
Ubuntu USN |
USN-8028-7 | Linux kernel (Low Latency NVIDIA) vulnerabilities |
Ubuntu USN |
USN-8028-8 | Linux kernel (IBM) vulnerabilities |
Ubuntu USN |
USN-8052-2 | Linux kernel (Xilinx) vulnerabilities |
Ubuntu USN |
USN-8074-1 | Linux kernel (Azure) vulnerabilities |
Ubuntu USN |
USN-8074-2 | Linux kernel (Azure FIPS) vulnerabilities |
Ubuntu USN |
USN-8126-1 | Linux kernel (Azure) vulnerabilities |
No CVSS v4.0
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.176% probability within 30 days)
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| Description | 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. | |
| Title | arm64/fpsimd: Avoid clobbering kernel FPSIMD state with SMSTOP | |
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