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CVE-2025-39816

Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
16/09/2025
Last modified:
14/01/2026

Description

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> io_uring/kbuf: always use READ_ONCE() to read ring provided buffer lengths<br /> <br /> Since the buffers are mapped from userspace, it is prudent to use<br /> READ_ONCE() to read the value into a local variable, and use that for<br /> any other actions taken. Having a stable read of the buffer length<br /> avoids worrying about it changing after checking, or being read multiple<br /> times.<br /> <br /> Similarly, the buffer may well change in between it being picked and<br /> being committed. Ensure the looping for incremental ring buffer commit<br /> stops if it hits a zero sized buffer, as no further progress can be made<br /> at that point.

Impact

Vector 3.x
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 5.50 MEDIUM
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): High

Base Score 3.x
5.50
Severity 3.x
MEDIUM

Vulnerable products and versions

CPE From Up to
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 6.12 (including) 6.12.49 (excluding)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 6.13 (including) 6.16.5 (excluding)
cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:*

To consult the complete list of CPE names with products and versions, see this page


References to Advisories, Solutions, and Tools