CVE-2023-53625
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Description
A NULL pointer dereference was found in the Linux kernel Intel i915 graphics driver's virtual GPU debugfs cleanup handling. A local user with privileges to unbind the i915 driver can trigger driver removal on systems with active virtual GPU instances, causing the cleanup path to attempt removing debugfs entries after the debugfs root has already been destroyed, which results in a NULL pointer dereference and denial of service through kernel crash.
Statement
The issue arises because of incorrect ordering in the driver removal sequence. When the i915 driver with GVT-g (GPU virtualization) support is unbound, the cleanup proceeds through multiple stages: driver removal, MDEV (mediated device) unregistration, and vGPU destruction. During vGPU destruction, the code unconditionally calls intel_gvt_debugfs_remove_vgpu() to clean up debugfs entries. However, at this point in the removal sequence, the DRM minor's debugfs root may have already been torn down. When debugfs_remove() attempts to lock the inode semaphore to recursively remove entries, it dereferences a NULL pointer (address 0x150, an offset into the destroyed debugfs inode structure), causing an immediate kernel oops. This occurs reliably on any system using GVT-g when the driver is unbound while virtual GPUs exist. The impact is strictly availability—the system crashes during driver removal. There is no memory corruption, information disclosure, or path to privilege escalation; the NULL dereference happens in lock acquisition code before any potentially dangerous operations could occur.
Mitigation
To mitigate this issue, prevent the kvmgt module from loading. See https://access.redhat.com/solutions/41278 for instructions on blacklisting kernel modules.
Additional Information
- This content is not included.Bugzilla 2402211: kernel: drm/i915/gvt: fix vgpu debugfs clean in remove
- Content from cwe.mitre.org is not included.CWE-476: NULL Pointer Dereference
- FAQ: Frequently asked questions about CVE-2023-53625
- 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-2023-53625
Content from nvd.nist.gov is not included.https://nvd.nist.gov/vuln/detail/CVE-2023-53625
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-rt | Fix deferred | |
| Red Hat Enterprise Linux 8 | kernel | Fixed | RHSA-2023:7077 |
| Red Hat Enterprise Linux 9 | kernel-rt | Fix deferred | |
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2023:6583 |
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?
My product is listed as "Out of Support Scope". What does this mean?
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