Linux: Double Free
CVE-2025-38421 is a high-severity double free vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions d6a38e1a82d2f9abd0bae84a354654bccb8389f6, 0d10b532f861253c283863522d59d099fcb0796d, d9db3a941270d92bbd1a6a6b54a10324484f2f2d as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.24% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to d6a38e1a82d2f9abd0bae84a354654bccb8389f6 or 0d10b532f861253c283863522d59d099fcb0796d or d9db3a941270d92bbd1a6a6b54a10324484f2f2d or 6.12.114, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.13 or 6.14 or 6.15.4, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | e70b4b8f93d7fcf8ee063a1d1f18782c4da3d335 up to, but not including, d6a38e1a82d2f9abd0bae84a354654bccb8389f6; 5b1122fc4995f308b21d7cfc64ef9880ac834d20 up to, but not including, 0d10b532f861253c283863522d59d099fcb0796d; 5b1122fc4995f308b21d7cfc64ef9880ac834d20 up to, but not including, d9db3a941270d92bbd1a6a6b54a10324484f2f2d; 3ed60e51ffdbfef14169bd967e21a6ba5e5ff42b; 6.12.23 up to, but not including, 6.12.114; 6.13.11 up to, but not including, 6.14; 6.14 | d6a38e1a82d2f9abd0bae84a354654bccb8389f6, 0d10b532f861253c283863522d59d099fcb0796d, d9db3a941270d92bbd1a6a6b54a10324484f2f2d, 6.12.114, 6.14 |
| Linux | Linux Kernel | 6.12.23 up to, but not including, 6.13; 6.13.11 up to, but not including, 6.14; 6.14.1 up to, but not including, 6.15.4; 6.14; 6.16 | 6.13, 6.14, 6.15.4 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: platform/x86/amd: pmf: Use device managed allocations If setting up smart PC fails for any reason then this can lead to a double free when unloading amd-pmf. This is because dev->buf was freed but never set to NULL and is again freed in amd_pmf_remove(). To avoid subtle allocation bugs in failures leading to a double free change all allocations into device managed allocations.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Double Free
The product calls free() twice on the same memory address.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly. If the language is object oriented, ensure that object destructors delete each chunk of memory only once.
- Use a static analysis tool to find double free instances.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Recent Double Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 8.2 High severity
Spotted an error? Tell us.