Linux: Double Free
CVE-2022-49391 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 adc02700236613b344a947a897fc2741d52a43b9, eac3e5b1c12f85732e60f5f8b985444d273866bb 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 0.25% 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 adc02700236613b344a947a897fc2741d52a43b9 or eac3e5b1c12f85732e60f5f8b985444d273866bb, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.18.4 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | c1407ac1099ab9726c31d38d806f3150f494c494 up to, but not including, adc02700236613b344a947a897fc2741d52a43b9; c1407ac1099ab9726c31d38d806f3150f494c494 up to, but not including, eac3e5b1c12f85732e60f5f8b985444d273866bb; 5.18 | adc02700236613b344a947a897fc2741d52a43b9, eac3e5b1c12f85732e60f5f8b985444d273866bb |
| Linux | Linux Kernel | 5.18 up to, but not including, 5.18.4 | 5.18.4 |
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 | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: remoteproc: mtk_scp: Fix a potential double free 'scp->rproc' is allocated using devm_rproc_alloc(), so there is no need to free it explicitly in the remove function.
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.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Double 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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