CVE-2023-52704: freezer,umh: Fix call_usermode_helper_exec() vs SIGKILL

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: 2024-05-21 · updated 2026-08-04

Description

In the Linux kernel, the following vulnerability has been resolved: freezer,umh: Fix call_usermode_helper_exec() vs SIGKILL Tetsuo-San noted that commit f5d39b020809 ("freezer,sched: Rewrite core freezer logic") broke call_usermodehelper_exec() for the KILLABLE case. Specifically it was missed that the second, unconditional, wait_for_completion() was not optional and ensures the on-stack completion is unused before going out-of-scope.

Affected products

Linux kernel: from 6.1 before 6.1.13; 6.2-rc1, 6.2-rc2, 6.2-rc3, 6.2-rc4, 6.2-rc5, 6.2-rc6 (+2) — fixed in 6.1.13

How to fix

Upgrade to a fixed version: Linux kernel 6.1.13. Check the vendor advisory for mitigations.

References

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