CVE-2025-38169
BaseFortify
Publication date: 2025-07-03
Last updated on: 2025-11-20
Assigner: kernel.org
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | From 5.15.160 (inc) to 5.16 (inc) |
| linux | linux_kernel | From 5.15.160 (inc) to 5.16 (inc) |
| linux | linux_kernel | From 5.15.160 (inc) to 5.16 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-NVD-CWE-noinfo |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability occurs in the Linux kernel on systems with SME (Scalable Matrix Extension). When a thread's kernel FPSIMD (Floating Point and SIMD) state is restored during a context switch, if the CPU is in streaming SVE (Scalable Vector Extension) mode, the FPSIMD state can be clobbered due to the order of operations. Specifically, fpsimd_thread_switch() restores the FPSIMD state while still in streaming SVE mode, then calls fpsimd_flush_cpu_state(), which executes an SMSTOP instruction causing an exit from streaming SVE mode. This exit resets several FPSIMD/SVE/SME registers, corrupting the FPSIMD state. The fix involves calling fpsimd_flush_cpu_state() before restoring the FPSIMD state to prevent this clobbering.
How can this vulnerability impact me? :
This vulnerability can cause the kernel FPSIMD state to be corrupted during context switches on systems with SME. This could lead to incorrect floating point or SIMD computations in kernel threads, potentially causing system instability, incorrect processing results, or crashes in affected workloads that rely on these CPU features.
What immediate steps should I take to mitigate this vulnerability?
Apply the Linux kernel update that includes the fix for this vulnerability, which ensures that fpsimd_flush_cpu_state() is called before restoring the kernel FPSIMD state to prevent clobbering. Systems without SME are unaffected, so mitigation is primarily through updating the kernel to a patched version.