io_uring/kbuf: always use READ_ONCE() to read ring provided buffer lengths
Summary
| CVE | CVE-2025-39816 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2025-09-16 13:15:56 UTC |
| Updated | 2026-04-11 13:16:35 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: io_uring/kbuf: always use READ_ONCE() to read ring provided buffer lengths Since the buffers are mapped from userspace, it is prudent to use READ_ONCE() to read the value into a local variable, and use that for any other actions taken. Having a stable read of the buffer length avoids worrying about it changing after checking, or being read multiple times. Similarly, the buffer may well change in between it being picked and being committed. Ensure the looping for incremental ring buffer commit stops if it hits a zero sized buffer, as no further progress can be made at that point. |
Risk And Classification
Primary CVSS: v3.1 5.5 MEDIUM from [email protected]
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Problem Types: NVD-CWE-noinfo | CWE-noinfo Not enough information
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 5.5 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | ADP | DECLARED | 5.5 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | Secondary | 5.5 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Operating System | Linux | Linux Kernel | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected ae98dbf43d755b4e111fcd086e53939bef3e9a1a 695673eb5711ee5eb1769481cf1503714716a7d1 git | Not specified |
| CNA | Linux | Linux | affected ae98dbf43d755b4e111fcd086e53939bef3e9a1a 91f262ea2a76a02d9e37dba6637cfe6feebb20a8 git | Not specified |
| CNA | Linux | Linux | affected ae98dbf43d755b4e111fcd086e53939bef3e9a1a 390a61d284e1ced088d43928dfcf6f86fffdd780 git | Not specified |
| CNA | Linux | Linux | affected ae98dbf43d755b4e111fcd086e53939bef3e9a1a 98b6fa62c84f2e129161e976a5b9b3cb4ccd117b git | Not specified |
| CNA | Linux | Linux | affected 6.12 | Not specified |
| CNA | Linux | Linux | unaffected 6.12 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.49 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.81 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.16.5 6.16.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.17 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/98b6fa62c84f2e129161e976a5b9b3cb4ccd117b | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/695673eb5711ee5eb1769481cf1503714716a7d1 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/390a61d284e1ced088d43928dfcf6f86fffdd780 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/91f262ea2a76a02d9e37dba6637cfe6feebb20a8 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.