Linux: Use After Free
CVE-2025-38595 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 2be49867e68abbeb52d7f5d15eb1216154e2c0a0, ba8bc644f168509c16d48444991de7cfea3f12ec, e5907885260401bba300d4d18d79875c05b82651 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 0.23% 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 2be49867e68abbeb52d7f5d15eb1216154e2c0a0 or ba8bc644f168509c16d48444991de7cfea3f12ec or e5907885260401bba300d4d18d79875c05b82651 or 3edfd2353f301bfffd5ee41066e37320a59ccc2d, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.42 or 6.15.10 or 6.16.1, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | a240d6e42e28c34fdc34b3a98ca838a31c939901 up to, but not including, 2be49867e68abbeb52d7f5d15eb1216154e2c0a0; a240d6e42e28c34fdc34b3a98ca838a31c939901 up to, but not including, ba8bc644f168509c16d48444991de7cfea3f12ec; a240d6e42e28c34fdc34b3a98ca838a31c939901 up to, but not including, e5907885260401bba300d4d18d79875c05b82651; a240d6e42e28c34fdc34b3a98ca838a31c939901 up to, but not including, 3edfd2353f301bfffd5ee41066e37320a59ccc2d; a240d6e42e28c34fdc34b3a98ca838a31c939901 up to, but not including, d59d49af4aeed9a81e673e37c26c6a3bacf1a181; a240d6e42e28c34fdc34b3a98ca838a31c939901 up to, but not including, 532c8b51b3a8676cbf533a291f8156774f30ea87; 4.19 | 2be49867e68abbeb52d7f5d15eb1216154e2c0a0, ba8bc644f168509c16d48444991de7cfea3f12ec, e5907885260401bba300d4d18d79875c05b82651, 3edfd2353f301bfffd5ee41066e37320a59ccc2d, d59d49af4aeed9a81e673e37c26c6a3bacf1a181, 532c8b51b3a8676cbf533a291f8156774f30ea87 |
| Linux | Linux Kernel | 4.19 up to, but not including, 6.12.42; 6.13 up to, but not including, 6.15.10; 6.16 up to, but not including, 6.16.1 | 6.12.42, 6.15.10, 6.16.1 |
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: xen: fix UAF in dmabuf_exp_from_pages() [dma_buf_fd() fixes; no preferences regarding the tree it goes through - up to xen folks] As soon as we'd inserted a file reference into descriptor table, another thread could close it. That's fine for the case when all we are doing is returning that descriptor to userland (it's a race, but it's a userland race and there's nothing the kernel can do about it). However, if we follow fd_install() with any kind of access to objects that would be destroyed on close (be it the struct file itself or anything destroyed by its ->release()), we have a UAF. dma_buf_fd() is a combination of reserving a descriptor and fd_install(). gntdev dmabuf_exp_from_pages() calls it and then proceeds to access the objects destroyed on close - starting with gntdev_dmabuf itself. Fix that by doing reserving descriptor before anything else and do fd_install() only when everything had been set up.
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
Other references
Recent Use After Free vulnerabilities
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