CVE-2024-39479

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Last Modified: UTC

Description

The MITRE CVE dictionary describes this issue as

In the Linux kernel, the following vulnerability has been resolved: drm/i915/hwmon: Get rid of devm When both hwmon and hwmon drvdata (on which hwmon depends) are device managed resources, the expectation, on device unbind, is that hwmon will be released before drvdata. However, in i915 there are two separate code paths, which both release either drvdata or hwmon and either can be released before the other. These code paths (for device unbind) are as follows (see also the bug referenced below): Call Trace: release_nodes+0x11/0x70 devres_release_group+0xb2/0x110 component_unbind_all+0x8d/0xa0 component_del+0xa5/0x140 intel_pxp_tee_component_fini+0x29/0x40 [i915] intel_pxp_fini+0x33/0x80 [i915] i915_driver_remove+0x4c/0x120 [i915] i915_pci_remove+0x19/0x30 [i915] pci_device_remove+0x32/0xa0 device_release_driver_internal+0x19c/0x200 unbind_store+0x9c/0xb0 and Call Trace: release_nodes+0x11/0x70 devres_release_all+0x8a/0xc0 device_unbind_cleanup+0x9/0x70 device_release_driver_internal+0x1c1/0x200 unbind_store+0x9c/0xb0 This means that in i915, if use devm, we cannot gurantee that hwmon will always be released before drvdata. Which means that we have a uaf if hwmon sysfs is accessed when drvdata has been released but hwmon hasn't. The only way out of this seems to be do get rid of devm_ and release/free everything explicitly during device unbind. v2: Change commit message and other minor code changes v3: Cleanup from i915_hwmon_register on error (Armin Wolf) v4: Eliminate potential static analyzer warning (Rodrigo) Eliminate fetch_and_zero (Jani) v5: Restore previous logic for ddat_gt->hwmon_dev error return (Andi)

Affected Packages and Issued Red Hat Security Errata

Products / Services Components State Errata
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 Fix deferred
Red Hat Enterprise Linux 8 kernel-rt Fix deferred
Red Hat Enterprise Linux 9 kernel-rt Affected
Red Hat Enterprise Linux 9 kernel Fixed This content is not included.RHSA-2024:9315
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.

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 4.4 7.8
Attack Vector Local Local
Attack Complexity Low Low
Privileges Required High Low
User Interaction None None
Scope Unchanged Unchanged
Confidentiality Impact None High
Integrity Impact None High
Availability Impact High High

CVSS v3 Vector

Red Hat CVSS:3.1/AV:L/AC:L/PR:H/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:H/I:H/A:H

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

For open source software shipped by multiple vendors, the CVSS base scores may vary for each vendor's version depending on the version they ship, how they ship it, the platform, and even how the software is compiled. This makes scoring of vulnerabilities difficult for third-party vulnerability databases such as NVD that only provide a single CVSS base score for each vulnerability. Red Hat scores reflect how a vulnerability affects our products specifically.

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"?

A "will not fix" status means that a fix for an affected product version is not planned or not possible due to complexity, which may create additional risk.

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"?

A deferred status means that a fix for an affected product version is not guaranteed due to higher-priority development work.

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?

A mitigation is an action that can be taken to reduce the impact of a security vulnerability, without deploying any fixes.

I have a Red Hat product but it is not in the above list, is it affected?

The listed products were found to include one or more of the components that this vulnerability affects. These products underwent a thorough evaluation to determine their affectedness by this vulnerability. Note that layered products (such as container-based offerings) that consume affected components from any of the products listed in this table may be affected and are not represented.

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

In order to maintain code stability and compatibility, Red Hat usually does not rebase packages to entirely new versions. Instead, we backport fixes and new features to an older version of the package we distribute. This can result in some security scanners that only consider the package version to report the package as vulnerable. To avoid this, we suggest that you use an approved vulnerability scanner from our This content is not included.Red Hat Vulnerability Scanner Certification program.