Linux: Use After Free
CVE-2022-48789 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 61a26ffd5ad3ece456d74c4c79f7b5e3f440a141, e192184cf8bce8dd55d619f5611a2eaba996fa05, 5e42fca37ccc76f39f73732661bd47254cad5982 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 0.66% chance of exploitation within 30 days, higher than 52% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 61a26ffd5ad3ece456d74c4c79f7b5e3f440a141 or e192184cf8bce8dd55d619f5611a2eaba996fa05 or 5e42fca37ccc76f39f73732661bd47254cad5982 or bb0d8fb35c4ff00a503c2c4dca4cce8d102a21c4, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.4.181 or 5.10.102 or 5.15.25 or 5.16.11, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 3f2304f8c6d6ed97849057bd16fee99e434ca796 up to, but not including, 61a26ffd5ad3ece456d74c4c79f7b5e3f440a141; 3f2304f8c6d6ed97849057bd16fee99e434ca796 up to, but not including, e192184cf8bce8dd55d619f5611a2eaba996fa05; 3f2304f8c6d6ed97849057bd16fee99e434ca796 up to, but not including, 5e42fca37ccc76f39f73732661bd47254cad5982; 3f2304f8c6d6ed97849057bd16fee99e434ca796 up to, but not including, bb0d8fb35c4ff00a503c2c4dca4cce8d102a21c4; 3f2304f8c6d6ed97849057bd16fee99e434ca796 up to, but not including, ff9fc7ebf5c06de1ef72a69f9b1ab40af8b07f9e; 5.0 | 61a26ffd5ad3ece456d74c4c79f7b5e3f440a141, e192184cf8bce8dd55d619f5611a2eaba996fa05, 5e42fca37ccc76f39f73732661bd47254cad5982, bb0d8fb35c4ff00a503c2c4dca4cce8d102a21c4, ff9fc7ebf5c06de1ef72a69f9b1ab40af8b07f9e |
| Linux | Linux Kernel | before 5.4.181; 5.5 up to, but not including, 5.10.102; 5.11 up to, but not including, 5.15.25; 5.16 up to, but not including, 5.16.11 | 5.4.181, 5.10.102, 5.15.25, 5.16.11 |
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 | 9.8 | Critical | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: nvme-tcp: fix possible use-after-free in transport error_recovery work While nvme_tcp_submit_async_event_work is checking the ctrl and queue state before preparing the AER command and scheduling io_work, in order to fully prevent a race where this check is not reliable the error recovery work must flush async_event_work before continuing to destroy the admin queue after setting the ctrl state to RESETTING such that there is no race .submit_async_event and the error recovery handler itself changing the ctrl state.
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
- git.kernel.org/stable/c/5e42fca37ccc76f39f73732661bd47254cad5982
- git.kernel.org/stable/c/61a26ffd5ad3ece456d74c4c79f7b5e3f440a141
- git.kernel.org/stable/c/bb0d8fb35c4ff00a503c2c4dca4cce8d102a21c4
- git.kernel.org/stable/c/e192184cf8bce8dd55d619f5611a2eaba996fa05
- git.kernel.org/stable/c/ff9fc7ebf5c06de1ef72a69f9b1ab40af8b07f9e
Recent Use After Free vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
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