CVE-2026-64067
Received Received - Intake

Race Condition in Linux Kernel Netfs Stream Handling

Vulnerability report for CVE-2026-64067, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-07-19

Last updated on: 2026-07-19

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: netfs: Fix missing barriers when accessing stream->subrequests locklessly The list of subrequests attached to stream->subrequests is accessed without locks by netfs_collect_read_results() and netfs_collect_write_results(), and then they access subreq->flags without taking a barrier after getting the subreq pointer from the list. Relatedly, the functions that build the list don't use any sort of write barrier when constructing the list to make sure that the NETFS_SREQ_IN_PROGRESS flag is perceived to be set first if no lock is taken. Fix this by: (1) Add a new list_add_tail_release() function that uses a release barrier to set the pointer to the new member of the list. (2) Add a new list_first_entry_or_null_acquire() function that uses an acquire barrier to read the pointer to the first member in a list (or return NULL). (3) Use list_add_tail_release() when adding a subreq to ->subrequests. (4) Use list_first_entry_or_null_acquire() when initially accessing the front of the list (when an item is removed, the pointer to the new front iterm is obtained under the same lock).

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Meta Information

Published
2026-07-19
Last Modified
2026-07-19
Generated
2026-07-20
AI Q&A
2026-07-19
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *

Helpful Resources

Exploitability

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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves improper handling of the stream->subrequests list. Functions like netfs_collect_read_results() and netfs_collect_write_results() access this list without locks, leading to potential race conditions. The issue arises because the flags of subrequests are accessed without memory barriers after retrieving pointers from the list. The fix introduces new functions with proper memory barriers to ensure correct ordering of operations.

Detection Guidance

This vulnerability is specific to the Linux kernel's netfs subsystem and requires kernel-level inspection. Detection involves checking kernel logs for related errors or verifying the presence of the vulnerable code paths. Commands like dmesg, journalctl, or examining kernel source code may help identify affected systems.

Impact Analysis

This vulnerability could lead to data corruption or crashes in systems using the Linux kernel's netfs subsystem. If exploited, it may cause inconsistent or incorrect handling of read/write operations, potentially resulting in system instability or security issues. Systems relying on netfs for file operations are most at risk.

Compliance Impact

This vulnerability does not directly affect compliance with standards like GDPR or HIPAA as it pertains to a race condition in the Linux kernel's netfs subsystem. Compliance impacts would depend on system-specific usage and data handling rather than this technical flaw.

Mitigation Strategies

Apply the latest kernel patches or updates that include the fix for this issue. If patches are unavailable, consider disabling affected netfs features or isolating systems using the vulnerable kernel until updates are applied.

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