Linux: Use After Free
CVE-2022-50137 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 92520864ef9f912f38b403d172a0ded020683d55, 0abf2eef80295923b819ce89ff9edc1fe61be17c, 350ac793a03c8a30a3f2b27fc282cd1c67070763 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 92520864ef9f912f38b403d172a0ded020683d55 or 0abf2eef80295923b819ce89ff9edc1fe61be17c or 350ac793a03c8a30a3f2b27fc282cd1c67070763 or 8ecef7890b3aea78c8bbb501a4b5b8134367b821, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.15.61 or 5.18.18 or 5.19.2, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | b48c24c2d710cf34810c555dcef883a3d35a9c08 up to, but not including, 92520864ef9f912f38b403d172a0ded020683d55; b48c24c2d710cf34810c555dcef883a3d35a9c08 up to, but not including, 0abf2eef80295923b819ce89ff9edc1fe61be17c; b48c24c2d710cf34810c555dcef883a3d35a9c08 up to, but not including, 350ac793a03c8a30a3f2b27fc282cd1c67070763; b48c24c2d710cf34810c555dcef883a3d35a9c08 up to, but not including, 8ecef7890b3aea78c8bbb501a4b5b8134367b821; 5.14 | 92520864ef9f912f38b403d172a0ded020683d55, 0abf2eef80295923b819ce89ff9edc1fe61be17c, 350ac793a03c8a30a3f2b27fc282cd1c67070763, 8ecef7890b3aea78c8bbb501a4b5b8134367b821 |
| Linux | Linux Kernel | 5.14 up to, but not including, 5.15.61; 5.16 up to, but not including, 5.18.18; 5.19 up to, but not including, 5.19.2 | 5.15.61, 5.18.18, 5.19.2 |
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: RDMA/irdma: Fix a window for use-after-free During a destroy CQ an interrupt may cause processing of a CQE after CQ resources are freed by irdma_cq_free_rsrc(). Fix this by moving the call to irdma_cq_free_rsrc() after the irdma_sc_cleanup_ceqes(), which is called under the cq_lock.
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
Recent Use After Free vulnerabilities
- 8.8 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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