Race Condition in Linux Kernel Unix GC Mechanism

Publication date: 2026-07-04

Last updated on: 2026-07-22

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: af_unix: Set gc_in_progress to true in unix_gc(). Igor Ushakov reported that unix_gc() could run with gc_in_progress being false if the work is scheduled while running: Thread 1 Thread 2 Thread 3 -------- -------- -------- unix_schedule_gc() unix_schedule_gc() `- if (!gc_in_progress) `- if (!gc_in_progress) |- gc_in_progress = true | `- queue_work() | unix_gc() <----------------/ | | |- gc_in_progress = true ... `- queue_work() | | `- gc_in_progress = false | | unix_gc() <---------------------------------------------' | ... /* gc_in_progress == false */ | `- gc_in_progress = false unix_peek_fpl() relies on gc_in_progress not to confuse GC by MSG_PEEK. Let's set gc_in_progress to true in unix_gc().

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Meta Information

Published

2026-07-04

Last Modified

2026-07-22

Generated

2026-07-24

AI Q&A

2026-07-04

EPSS Evaluated

2026-07-23

NVD

CVE-2026-53361

EUVD

EUVD-2026-41668

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	From 6.1.141 (inc) to 6.2 (exc)
linux	linux_kernel	7.1
linux	linux_kernel	7.1
linux	linux_kernel	From 6.9 (inc) to 6.12.95 (exc)
linux	linux_kernel	From 6.13 (inc) to 6.18.38 (exc)
linux	linux_kernel	From 6.19 (inc) to 7.1 (exc)
linux	linux_kernel	From 6.6.93 (inc) to 6.6.144 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability exists in the Linux kernel's af_unix subsystem related to garbage collection (GC) management. Specifically, the function unix_gc() could run with the variable gc_in_progress set to false due to a race condition when multiple threads schedule garbage collection work concurrently. This could cause confusion in the garbage collection process, especially since unix_peek_fpl() relies on gc_in_progress being true to avoid misinterpreting MSG_PEEK operations. The fix involves setting gc_in_progress to true within unix_gc() to ensure proper synchronization.

Impact Analysis

This vulnerability can lead to incorrect garbage collection behavior in the Linux kernel's af_unix subsystem. Because gc_in_progress might be false when it should be true, the system could confuse garbage collection with MSG_PEEK operations, potentially causing resource mismanagement or unexpected behavior in inter-process communication over Unix sockets.

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