CVE-2025-38113: ACPI: CPPC: Fix NULL pointer dereference when nosmp is used

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-07-03 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: ACPI: CPPC: Fix NULL pointer dereference when nosmp is used With nosmp in cmdline, other CPUs are not brought up, leaving their cpc_desc_ptr NULL. CPU0's iteration via for_each_possible_cpu() dereferences these NULL pointers, causing panic. Panic backtrace: [ 0.401123] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000b8 ... [ 0.403255] [<ffffffff809a5818>] cppc_allow_fast_switch+0x6a/0xd4 ... Kernel panic - not syncing: Attempted to kill init! [ rjw: New subject ]

Affected products

Debian Linux: 11.0
Linux kernel: from 5.19 before 6.1.142; from 6.2 before 6.6.94; from 6.7 before 6.12.34; from 6.13 before 6.15.3; 6.16-rc1 — fixed in 6.1.142, 6.12.34, 6.15.3, 6.6.94

How to fix

Upgrade to a fixed version: Linux kernel 6.1.142, 6.12.34, 6.15.3, 6.6.94. Check the vendor advisory for mitigations.

References

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