CVE-2026-64216 Details
Description
In the Linux kernel, the following vulnerability has been resolved: netfs: Fix potential UAF in netfs_unlock_abandoned_read_pages() netfs_unlock_abandoned_read_pages(rreq) accesses the index of the folios it is wanting to unlock and compares that to rreq->no_unlock_folio so that it doesn't unlock a folio being read for netfs_perform_write() or netfs_write_begin(). However, given that netfs_unlock_abandoned_read_pages() is called _after_ NETFS_RREQ_IN_PROGRESS is cleared, the one folio that it's not allowed to dereference is the one specified by ->no_unlock_folio as ownership immediately reverts to the caller. Fix this by storing the folio pointer instead and using that rather than the index. Also fix netfs_unlock_read_folio() where the same applies.
A use-after-free vulnerability has been identified in the Linux kernel's netfs component, specifically within the netfs_unlock_abandoned_read_pages function. This vulnerability arises because the function accesses folio indices to determine which folios to unlock, comparing them to a request parameter that indicates which folio should not be unlocked. The issue occurs because netfs_unlock_abandoned_read_pages is called after a specific request flag is cleared, allowing ownership of the folio to revert to the caller. As a result, the function can inadvertently reference a folio that is still being read for write operations, leading to potential memory management issues. The vulnerability affects several versions of the Linux kernel.
Users can upgrade to the latest version of the Linux kernel where this vulnerability has been addressed. Instructions for upgrading the Linux kernel can be found in the official Linux kernel documentation.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/3866d015f33aeedf81338dd99154703bef33faef | kernel.org | Patch |
| https://git.kernel.org/stable/c/6080fa3ecfbb4448a3b47368629534c09b6ec750 | kernel.org | Patch |
| https://git.kernel.org/stable/c/d4ae8dba90b89e7bb4d1045d1cb26afbaf13ee5c | kernel.org | |
| https://git.kernel.org/stable/c/dbe556972100fabb8e5a1b3d2163831ff07b1e8e | kernel.org | Patch |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-416 | Use After Free | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | >= 6.12, < 6.18.34 >= 6.19, < 7.0.11 7.1 rc1 7.1 rc2 7.1 rc3 7.1 rc4 |
CPE
Remediation
| |
Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Aug 27, 2026 | CVE Modified | kernel.org |
| Aug 11, 2026 | Initial Analysis | [email protected] |
| Jul 27, 2026 | CVE Modified | kernel.org |
| Jul 24, 2026 | New CVE Received | kernel.org |