CVE-2022-50495
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Description
A memory leak was found in the Linux kernel's Xen SMP interrupt initialization functions for x86 architectures. When interrupt handler binding fails during setup, the error path frees various resources but neglects to free dynamically allocated interrupt name strings created via kasprintf. This causes memory to leak with each failed initialization attempt, leading to resource exhaustion and denial of service.
Statement
The Xen SMP initialization code creates descriptive names for various inter-processor interrupts (IPIs) like reschedule, PMU, and call-function interrupts. These names are allocated dynamically using kasprintf and stored in local variables. When bind_ipi_to_irqhandler or bind_virq_to_irqhandler fails to register an interrupt handler, execution jumps to an error label that invokes xen_smp_intr_free (or xen_smp_intr_free_pv) to clean up. This cleanup releases the interrupt handlers themselves, but since the kasprintf-allocated strings were never stored in any structure that the cleanup function can access, they're simply abandoned in memory. Each initialization failure therefore leaks small amounts of memory—individually insignificant, but potentially problematic during repeated initialization cycles or in environments where Xen SMP setup repeatedly fails. The fix stores these strings where the cleanup path can find and free them.
Additional Information
- This content is not included.Bugzilla 2401512: kernel: x86/xen: Fix memory leak in xen_smp_intr_init{_pv}()
- Content from cwe.mitre.org is not included.CWE-772: Missing Release of Resource after Effective Lifetime
- FAQ: Frequently asked questions about CVE-2022-50495
- 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-2022-50495
Content from nvd.nist.gov is not included.https://nvd.nist.gov/vuln/detail/CVE-2022-50495
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 | Out of support scope | |
| Red Hat Enterprise Linux 7 | kernel | Fix deferred | |
| Red Hat Enterprise Linux 7 | kernel-rt | Fix deferred | |
| Red Hat Enterprise Linux 8 | kernel-rt | Fix deferred | |
| Red Hat Enterprise Linux 8 | kernel | Fixed | RHSA-2024:5101 |
| Red Hat Enterprise Linux 8.2 Advanced Update Support | kernel | Fixed | RHSA-2024:6992 |
| Red Hat Enterprise Linux 9 | kernel-rt | Fix deferred | |
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2024:5928 |
| Red Hat Enterprise Linux 9 | kernel | Fixed | This content is not included.RHSA-2024:9315 |
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 | |
| Attack Vector | Local | |
| Attack Complexity | Low | |
| Privileges Required | Low | |
| User Interaction | None | |
| Scope | Unchanged | |
| Confidentiality Impact | None | |
| Integrity Impact | None | |
| Availability Impact | 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
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?
My product is listed as "Out of Support Scope". What does this mean?
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