CVE-2025-40174

x86/mm: Fix SMP ordering in switch_mm_irqs_off()

State: Published
Severity: 7.8 High
Published: Nov 12, 2025
Updated: Aug 5, 2026
Reserved: Apr 16, 2025

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 ]

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	209954cbc7d0ce1a190fc725d20ce303d74d2680 to before 0fe5e3f5fb75c5d88dad24dece3ee75e9d87adebAffected 209954cbc7d0ce1a190fc725d20ce303d74d2680 to before 83b0177a6c4889b3a6e865da5e21b2c9d97d0551Affected
LinuxLinux	6.14Affected before 6.14Not affected 6.17.5 through 6.17.*Not affected 6.18 and laterNot affected

References

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