Linux: Double Free
CVE-2022-49384 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 36a2fc44c574a59ee3b5e2cb327182f227b2b07e, f99d5b5dc8a42c807b5f1176b925aa45d61962ab, ea7d7bd90079d96f9c86bdaf0b106e0cd2a70661 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 0.27% 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 36a2fc44c574a59ee3b5e2cb327182f227b2b07e or f99d5b5dc8a42c807b5f1176b925aa45d61962ab or ea7d7bd90079d96f9c86bdaf0b106e0cd2a70661 or 42b805af102471f53e3c7867b8c2b502ea4eef7e, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.15.46 or 5.17.14 or 5.18.3, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 00e3d58f50a875343124bcf5a9637520a492b0d1 up to, but not including, 36a2fc44c574a59ee3b5e2cb327182f227b2b07e; 0c031fd37f69deb0cd8c43bbfcfccd62ebd7e952 up to, but not including, f99d5b5dc8a42c807b5f1176b925aa45d61962ab; 0c031fd37f69deb0cd8c43bbfcfccd62ebd7e952 up to, but not including, ea7d7bd90079d96f9c86bdaf0b106e0cd2a70661; 0c031fd37f69deb0cd8c43bbfcfccd62ebd7e952 up to, but not including, 42b805af102471f53e3c7867b8c2b502ea4eef7e; 92053ae0398a58c6914e807d5e070297ba8cfe88; 5.15.17 up to, but not including, 5.15.46; 5.16.3 up to, but not including, 5.17; 5.17 | 36a2fc44c574a59ee3b5e2cb327182f227b2b07e, f99d5b5dc8a42c807b5f1176b925aa45d61962ab, ea7d7bd90079d96f9c86bdaf0b106e0cd2a70661, 42b805af102471f53e3c7867b8c2b502ea4eef7e, 5.15.46, 5.17 |
| Linux | Linux Kernel | 5.15.17 up to, but not including, 5.15.46; 5.16.3 up to, but not including, 5.17.14; 5.18 up to, but not including, 5.18.3 | 5.15.46, 5.17.14, 5.18.3 |
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: md: fix double free of io_acct_set bioset Now io_acct_set is alloc and free in personality. Remove the codes that free io_acct_set in md_free and md_stop.
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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