CVE-2025-40174
Published Nov 12, 2025
Modified Apr 15, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: x86/mm: Fix SMP ordering in switch_mm_irqs_off() Stephen noted that it is possible to not have an smp_mb() between the loaded_mm store and the tlb_gen load in switch_mm(), meaning the ordering against flush_tlb_mm_range() goes out the window, and it becomes possible for switch_mm() to not observe a recent tlb_gen update and fail to flush the TLBs. [ dhansen: merge conflict fixed by Ingo ]
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References
Frequently Asked Questions
What is CVE-2025-40174? +
In the Linux kernel, the following vulnerability has been resolved:
x86/mm: Fix SMP ordering in switch_mm_irqs_off()
Stephen noted that it is possible to not have an smp_mb() between
the loaded_mm store and the tlb_gen load in switch_mm(), meaning the
ordering against flush_tlb_mm_range() goes out the window, and it
becomes possible for switch_mm() to not observe a recent tlb_gen
update and fail to flush the TLBs.
[ dhansen: merge conflict fixed by Ingo ]
How do I check if I'm vulnerable to CVE-2025-40174? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.