CVE-2022-50491
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Description
A context violation bug was found in the Linux kernel's CoreSight CTI (Cross Trigger Interface) driver in the hardware enable/disable functions. These functions are called from atomic context but attempt runtime PM operations that can sleep when communicating with firmware. This causes "sleeping function called from invalid context" errors and system hangs when enabling CoreSight tracing, particularly on ARM Juno platforms, resulting in denial of service.
Statement
The CTI component coordinates debugging across multiple cores. When perf enables ETM (Embedded Trace Macrocell) tracing, it builds a trace path and enables each component along that path—including CTI devices. This happens under spinlocks in the perf event scheduling code, creating an atomic context where sleeping is forbidden. The cti_enable_hw and cti_disable_hw functions were calling pm_runtime_get and pm_runtime_put to manage power. These runtime PM calls can communicate with firmware (like ARM SCMI) to control clocks and power domains. Firmware communication typically involves waiting for responses, which means sleeping. Sleeping in atomic context triggers kernel warnings and can cause complete system hangs. The issue became more visible after a revert of SCMI power domain changes made the sleep more likely. The solution: remove the PM calls entirely from these functions. The runtime PM has already been handled at a higher level when building the trace path, so these redundant calls were both wrong and unnecessary.
Additional Information
- This content is not included.Bugzilla 2401482: kernel: coresight: cti: Fix hang in cti_disable_hw()
- Content from cwe.mitre.org is not included.CWE-1322: Use of Blocking Code in Single-threaded, Non-blocking Context
- FAQ: Frequently asked questions about CVE-2022-50491
- Offline Security Data data is available for integration with other systems. See Offline Security Data API to get started.
External References
Content from www.cve.org is not included.https://www.cve.org/CVERecord?id=CVE-2022-50491
Content from nvd.nist.gov is not included.https://nvd.nist.gov/vuln/detail/CVE-2022-50491
Affected Packages and Issued Red Hat Security Errata
| Products / Services | Components | State | Errata |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Not affected | |
| Red Hat Enterprise Linux 6 | kernel | Not affected | |
| Red Hat Enterprise Linux 7 | kernel | Not affected | |
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | |
| Red Hat Enterprise Linux 8 | kernel | Not affected | |
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | |
| Red Hat Enterprise Linux 9 | kernel-rt | Fix deferred | |
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2025:6966 |
Common Vulnerability Scoring System (CVSS) Score Details
Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authorities (CNA) source for its products and services (see Red Hat classifications ).
| CVSS v3 Score Breakdown | Red Hat | NVD |
|---|---|---|
| CVSS v3 Base Score | 5.5 | 5.5 |
| Attack Vector | Local | Local |
| Attack Complexity | Low | Low |
| Privileges Required | Low | Low |
| User Interaction | None | None |
| Scope | Unchanged | Unchanged |
| Confidentiality Impact | None | None |
| Integrity Impact | None | None |
| Availability Impact | High | High |
CVSS v3 Vector
Red Hat CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Frequently Asked Questions
Why is Red Hat's CVSS v3 score or Impact different from other vendors?
For more information, see https://access.redhat.com/solutions/762393.
My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?
- "Under investigation" doesn't necessarily mean that the product is affected by this vulnerability. It only means that our Analysis Team is still working on determining whether the product is affected and how it is affected.
- "Affected" means that our Analysis Team has determined that this product is affected by this vulnerability and might release a fix to address this in the near future.
What can I do if my product is listed as "Will not fix"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Upgrade to a supported product version that includes a fix for this vulnerability (recommended).
- Apply a mitigation (if one exists).
- Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
What can I do if my product is listed as "Fix deferred"?
Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
- Apply a mitigation (if one exists).
- Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
- Red Hat Engineering focuses on addressing high-priority issues based on their complexity or limited lifecycle support. Therefore, lower-priority issues will not receive immediate fixes.
What is a mitigation?
I have a Red Hat product but it is not in the above list, is it affected?
Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?
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