CVE-2023-53678
Public on
Last Modified:
Description
A NULL pointer dereference was found in the Linux kernel Intel i915 graphics driver's framebuffer device suspend handling. On platforms without display hardware where fbdev is not initialized, a local user with privileges to initiate system suspend can trigger the suspend path, causing the driver to attempt locking a mutex in the uninitialized fbdev structure, which results in a kernel NULL pointer dereference and denial of service through system crash.
Statement
The issue arises because the i915 driver's suspend path unconditionally attempts to suspend the framebuffer device without checking whether fbdev was successfully initialized. On platforms lacking display hardware (such as certain server or embedded configurations), fbdev initialization is skipped entirely, leaving the structure NULL. When system suspend is initiated through standard mechanisms (writing to /sys/power/state), the power management subsystem calls into the i915 driver's suspend handler, which then calls intel_fbdev_set_suspend(). This function attempts to acquire a mutex at offset 0x1c8 within the NULL fbdev structure, triggering an immediate kernel NULL pointer dereference. The crash occurs reliably on affected hardware configurations whenever suspend is attempted. While this is a severe availability issue causing complete system failure, exploitation is limited to users with privileges to initiate system suspend operations, and there is no memory corruption or information disclosure beyond the crash itself.
Mitigation
To mitigate this issue, prevent the i915 module from loading. See https://access.redhat.com/solutions/41278 for instructions on blacklisting kernel modules.
Additional information
- This content is not included.Bugzilla 2402217: kernel: drm/i915: Fix system suspend without fbdev being initialized
- Content from cwe.mitre.org is not included.CWE-476: NULL Pointer Dereference
Affected Packages and Issued Red Hat Security Errata
Unless explicitly stated as not affected, all previous versions of packages in any minor update stream of a product listed here should be assumed vulnerable, although may not have been subject to full analysis.
| 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 | Fix deferred | |
| Red Hat Enterprise Linux 9 | kernel-rt | Fix deferred |
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 | cve.org | |
|---|---|---|---|
| CVSS v3 Base Score | 5.5 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality Impact | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
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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