Linux: Use After Free
CVE-2024-38629 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 9eb15f24a0b9b017b39cde8b8c07243676b63687, 15edb906211bf53e7b5574f7326ab734d6bff4f9, 76e43fa6a456787bad31b8d0daeabda27351a480 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 9eb15f24a0b9b017b39cde8b8c07243676b63687 or 15edb906211bf53e7b5574f7326ab734d6bff4f9 or 76e43fa6a456787bad31b8d0daeabda27351a480, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.6.33 or 6.9.4, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | e6fd6d7e5f0fe4a17a08e892afb5db800e7794ec up to, but not including, 9eb15f24a0b9b017b39cde8b8c07243676b63687; e6fd6d7e5f0fe4a17a08e892afb5db800e7794ec up to, but not including, 15edb906211bf53e7b5574f7326ab734d6bff4f9; e6fd6d7e5f0fe4a17a08e892afb5db800e7794ec up to, but not including, 76e43fa6a456787bad31b8d0daeabda27351a480; 6.4 | 9eb15f24a0b9b017b39cde8b8c07243676b63687, 15edb906211bf53e7b5574f7326ab734d6bff4f9, 76e43fa6a456787bad31b8d0daeabda27351a480 |
| Linux | Linux Kernel | 6.4 up to, but not including, 6.6.33; 6.7 up to, but not including, 6.9.4 | 6.6.33, 6.9.4 |
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.
Official description
In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: Avoid unnecessary destruction of file_ida file_ida is allocated during cdev open and is freed accordingly during cdev release. This sequence is guaranteed by driver file operations. Therefore, there is no need to destroy an already empty file_ida when the WQ cdev is removed. Worse, ida_free() in cdev release may happen after destruction of file_ida per WQ cdev. This can lead to accessing an id in file_ida after it has been destroyed, resulting in a kernel panic. Remove ida_destroy(&file_ida) to address these issues.
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.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Use After Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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