Linux: Use After Free
CVE-2022-48792 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 fe9ac3eaa2e387a5742b380b73a5a6bc237bf184, d9d93f32534a0a80a1c26bdb0746d90a7b19c2c2, f61f9fccb2cb4bb275674a79d638704db6bc2171 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 0.24% 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 fe9ac3eaa2e387a5742b380b73a5a6bc237bf184 or d9d93f32534a0a80a1c26bdb0746d90a7b19c2c2 or f61f9fccb2cb4bb275674a79d638704db6bc2171 or df7abcaa1246e2537ab4016077b5443bb3c09378, whichever matches your release line, or a later version.
- Update Linux Kernel to 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 | 869ddbdcae3b4fb83b99889abae31544c149b210 up to, but not including, fe9ac3eaa2e387a5742b380b73a5a6bc237bf184; 869ddbdcae3b4fb83b99889abae31544c149b210 up to, but not including, d9d93f32534a0a80a1c26bdb0746d90a7b19c2c2; 869ddbdcae3b4fb83b99889abae31544c149b210 up to, but not including, f61f9fccb2cb4bb275674a79d638704db6bc2171; 869ddbdcae3b4fb83b99889abae31544c149b210 up to, but not including, df7abcaa1246e2537ab4016077b5443bb3c09378; 4.15 | fe9ac3eaa2e387a5742b380b73a5a6bc237bf184, d9d93f32534a0a80a1c26bdb0746d90a7b19c2c2, f61f9fccb2cb4bb275674a79d638704db6bc2171, df7abcaa1246e2537ab4016077b5443bb3c09378 |
| Linux | Linux Kernel | before 5.10.102; 5.11 up to, but not including, 5.15.25; 5.16 up to, but not including, 5.16.11 | 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 | 7.8 | High | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: scsi: pm8001: Fix use-after-free for aborted SSP/STP sas_task Currently a use-after-free may occur if a sas_task is aborted by the upper layer before we handle the I/O completion in mpi_ssp_completion() or mpi_sata_completion(). In this case, the following are the two steps in handling those I/O completions: - Call complete() to inform the upper layer handler of completion of the I/O. - Release driver resources associated with the sas_task in pm8001_ccb_task_free() call. When complete() is called, the upper layer may free the sas_task. As such, we should not touch the associated sas_task afterwards, but we do so in the pm8001_ccb_task_free() call. Fix by swapping the complete() and pm8001_ccb_task_free() calls ordering.
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
- 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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