CVE-2026-64057
afs: Fix the locking used by afs_get_link()
Description
In the Linux kernel, the following vulnerability has been resolved: afs: Fix the locking used by afs_get_link() The afs filesystem in the kernel doesn't do locking correctly for symbolic links. There are a number of problems: (1) It doesn't do any locking around afs_read_single() to prevent races between multiple ->get_link() calls, thereby allowing the possibility of leaks. (2) It doesn't use RCU barriering when accessing the buffer pointers during RCU pathwalk. (3) It can race with another thread updating the contents of the symlink if a third party updated it on the server. Fix this by the following means: (0) Move symlink handling into its own file as this makes it more complicated. (1) Take the validate_lock around afs_read_single() to prevent races between multiple ->get_link() calls. (2) Keep a separate copy of the symlink contents with an rcu_head. This is always going to be a lot smaller than a page, so it can be kmalloc'd and save quite a bit of memory. It also needs a refcount for non-RCU pathwalk. (3) Split the symlink read and write-to-cache routines in afs from those for directories. (4) Discard the I/O buffer as soon as the write-to-cache completes as this is a full page (plus a folio_queue). (5) If there's no cache, discard the I/O buffer immediately after reading and copying if there is no cache.
INFO
Published Date :
July 19, 2026, 4:17 p.m.
Last Modified :
July 20, 2026, 3:17 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-64057
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Update the Linux kernel to the latest version.
- Apply vendor-specific patches for the afs module.
- Review and test changes to symlink handling.
- Ensure proper RCU barrier usage in pathwalk.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-64057.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/77ea917cbed62882a33114b1e23ededb977e4287 | |
| https://git.kernel.org/stable/c/c0410adf3da6db46f3513411fcf95e63c2f1d1ad |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-64057 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-64057
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-64057 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-64057 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 20, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 19, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'eae9e78951bb02a7b94a9adef6e981413d13c564', 'lessThan': '77ea917cbed62882a33114b1e23ededb977e4287', 'versionType': 'git'}, {'status': 'affected', 'version': 'eae9e78951bb02a7b94a9adef6e981413d13c564', 'lessThan': 'c0410adf3da6db46f3513411fcf95e63c2f1d1ad', 'versionType': 'git'}], 'programFiles': ['fs/afs/Makefile', 'fs/afs/dir.c', 'fs/afs/fsclient.c', 'fs/afs/inode.c', 'fs/afs/internal.h', 'fs/afs/symlink.c', 'fs/afs/validation.c', 'fs/afs/yfsclient.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.14'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.14', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.0.11', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/afs/Makefile', 'fs/afs/dir.c', 'fs/afs/fsclient.c', 'fs/afs/inode.c', 'fs/afs/internal.h', 'fs/afs/symlink.c', 'fs/afs/validation.c', 'fs/afs/yfsclient.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: afs: Fix the locking used by afs_get_link() The afs filesystem in the kernel doesn't do locking correctly for symbolic links. There are a number of problems: (1) It doesn't do any locking around afs_read_single() to prevent races between multiple ->get_link() calls, thereby allowing the possibility of leaks. (2) It doesn't use RCU barriering when accessing the buffer pointers during RCU pathwalk. (3) It can race with another thread updating the contents of the symlink if a third party updated it on the server. Fix this by the following means: (0) Move symlink handling into its own file as this makes it more complicated. (1) Take the validate_lock around afs_read_single() to prevent races between multiple ->get_link() calls. (2) Keep a separate copy of the symlink contents with an rcu_head. This is always going to be a lot smaller than a page, so it can be kmalloc'd and save quite a bit of memory. It also needs a refcount for non-RCU pathwalk. (3) Split the symlink read and write-to-cache routines in afs from those for directories. (4) Discard the I/O buffer as soon as the write-to-cache completes as this is a full page (plus a folio_queue). (5) If there's no cache, discard the I/O buffer immediately after reading and copying if there is no cache. Added Reference https://git.kernel.org/stable/c/77ea917cbed62882a33114b1e23ededb977e4287 Added Reference https://git.kernel.org/stable/c/c0410adf3da6db46f3513411fcf95e63c2f1d1ad