CVE-2026-98388

Received Received - Intake

Linux Kernel exec_update_lock Race Condition Fix

Publication date: 2026-10-14

Last updated on: 2026-10-19

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: exec: do_close_on_exec() before taking exec_update_lock do_close_on_exec() currently happens while holding the exec_update_lock, which is used in a lot of places that access process state to synchronize access checks. I recently added another such use of exec_update_lock, causing a regression. do_close_on_exec() can block waiting for a reply from a filesystem. That means a hung filesystem can block codepaths that use exec_update_lock; and it also means that a FUSE filesystem which attempts to inspect the calling process can deadlock. To avoid such problems, move do_close_on_exec() before the exec_update_lock is taken, but after the FD table has been copied if necessary. I have looked through all the calls between the old and new position of the do_close_on_exec() call; there seems to be no file descriptor table access in between.

CVSS Scores

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Meta Information

Published

2026-10-14

Last Modified

2026-10-19

Generated

2026-10-19

AI Q&A

2026-10-15

EPSS Evaluated

2026-10-18

NVD

CVE-2026-98388

EUVD

EUVD-2026-101037

Affected Vendors & Products

Vendor	Product	Version / Range
Linux	Linux	ae1e630bcaac739f625822078edbaea98366930d
Linux	Linux	d54f14655fd7d7b293698a8b6918563c4c0465e7
Linux	Linux	bb43679356f1f2a4c6b1c88aec4f021e5b5c74e9
Linux	Linux	7456ae990a9738962b33146916fabca62ae3d4e0
Linux	Linux	4bfe8c481846cee52473a2f7d7b30ee8e6749fc4
Linux	Linux	f9b4b03ccc9c69bf7f7298d4559906ebea7143b3
Linux	Linux	6650527444dadc63d84aa939d14ecba4fadb2f69
Linux	Linux	6650527444dadc63d84aa939d14ecba4fadb2f69
Linux	Linux	c1cfd63326f5d09999134e9052c353faf738286e
Linux	Linux	5.10.261
Linux	Linux	5.15.212
Linux	Linux	6.1.178
Linux	Linux	6.6.145
Linux	Linux	6.12.97
Linux	Linux	6.18.40
Linux	Linux	7.1.4
Linux	Linux	7.2

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This is a Linux kernel vulnerability where do_close_on_exec() is called while holding the exec_update_lock, which synchronizes access to process state. This can cause deadlocks if do_close_on_exec() blocks waiting for a filesystem reply, especially with FUSE filesystems that inspect the calling process. The fix moves do_close_on_exec() before taking the exec_update_lock.

Detection Guidance

This vulnerability is specific to the Linux kernel and relates to a race condition in exec handling. Detection requires checking the kernel version and verifying if the fix is applied. Use uname -a to check kernel version and compare against patched versions.

Impact Analysis

A hung or malicious filesystem could cause system hangs or deadlocks during process execution. This may lead to system instability, unresponsive applications, or denial of service if exploited.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards. It is a Linux kernel execution flow issue that could lead to deadlocks or hung filesystems but does not involve data exposure, unauthorized access, or privacy violations typically addressed by these regulations.

Mitigation Strategies

Apply the latest kernel update from your Linux distribution to ensure the fix for CVE-2026-98388 is included. Reboot the system after updating to activate the patched kernel.

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