Linux: Use After Free
CVE-2025-38131 is a high-severity use after 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 dfe8224c9c7a43d356eb9f74b06868aa05f90223, b3b4efa2e623aecaebd7c9b9e4171f5c659e9724, 31028812724cef7bd57a51525ce58a32a6d73b22 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 0.2% 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 dfe8224c9c7a43d356eb9f74b06868aa05f90223 or b3b4efa2e623aecaebd7c9b9e4171f5c659e9724 or 31028812724cef7bd57a51525ce58a32a6d73b22 or ed42ee1ed05ff2f4c36938379057413a40c56680, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.142 or 6.6.94 or 6.12.34 or 6.15.3, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | f8cce2ff3c04361b8843d8489620fda8880f668b up to, but not including, dfe8224c9c7a43d356eb9f74b06868aa05f90223; f8cce2ff3c04361b8843d8489620fda8880f668b up to, but not including, b3b4efa2e623aecaebd7c9b9e4171f5c659e9724; f8cce2ff3c04361b8843d8489620fda8880f668b up to, but not including, 31028812724cef7bd57a51525ce58a32a6d73b22; f8cce2ff3c04361b8843d8489620fda8880f668b up to, but not including, ed42ee1ed05ff2f4c36938379057413a40c56680; f8cce2ff3c04361b8843d8489620fda8880f668b up to, but not including, 408c97c4a5e0b634dcd15bf8b8808b382e888164; 5.15 | dfe8224c9c7a43d356eb9f74b06868aa05f90223, b3b4efa2e623aecaebd7c9b9e4171f5c659e9724, 31028812724cef7bd57a51525ce58a32a6d73b22, ed42ee1ed05ff2f4c36938379057413a40c56680, 408c97c4a5e0b634dcd15bf8b8808b382e888164 |
| Linux | Linux Kernel | 5.15 up to, but not including, 6.1.142; 6.2 up to, but not including, 6.6.94; 6.7 up to, but not including, 6.12.34; 6.13 up to, but not including, 6.15.3 | 6.1.142, 6.6.94, 6.12.34, 6.15.3 |
| Debian | Debian Linux | 11.0 | Not stated |
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.
Official description
In the Linux kernel, the following vulnerability has been resolved: coresight: prevent deactivate active config while enabling the config While enable active config via cscfg_csdev_enable_active_config(), active config could be deactivated via configfs' sysfs interface. This could make UAF issue in below scenario: CPU0 CPU1 (sysfs enable) load module cscfg_load_config_sets() activate config. // sysfs (sys_active_cnt == 1) ... cscfg_csdev_enable_active_config() lock(csdev->cscfg_csdev_lock) // here load config activate by CPU1 unlock(csdev->cscfg_csdev_lock) deactivate config // sysfs (sys_activec_cnt == 0) cscfg_unload_config_sets() unload module // access to config_desc which freed // while unloading module. cscfg_csdev_enable_config To address this, use cscfg_config_desc's active_cnt as a reference count which will be holded when - activate the config. - enable the activated config. and put the module reference when config_active_cnt == 0.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/31028812724cef7bd57a51525ce58a32a6d73b22
- git.kernel.org/stable/c/408c97c4a5e0b634dcd15bf8b8808b382e888164
- git.kernel.org/stable/c/b3b4efa2e623aecaebd7c9b9e4171f5c659e9724
- git.kernel.org/stable/c/dfe8224c9c7a43d356eb9f74b06868aa05f90223
- git.kernel.org/stable/c/ed42ee1ed05ff2f4c36938379057413a40c56680
Third-party and government advisories
- lists.debian.org/debian-lts-announce/2025/10/msg00008.htmlThird Party Advisory
Recent Use After Free vulnerabilities
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- 7.8 High severity
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