CVE-2022-50214

Public on

Last Modified: UTC

Description

The MITRE CVE dictionary describes this issue as

In the Linux kernel, the following vulnerability has been resolved: coresight: Clear the connection field properly coresight devices track their connections (output connections) and hold a reference to the fwnode. When a device goes away, we walk through the devices on the coresight bus and make sure that the references are dropped. This happens both ways: a) For all output connections from the device, drop the reference to the target device via coresight_release_platform_data() b) Iterate over all the devices on the coresight bus and drop the reference to fwnode if *this* device is the target of the output connection, via coresight_remove_conns()->coresight_remove_match(). However, the coresight_remove_match() doesn't clear the fwnode field, after dropping the reference, this causes use-after-free and additional refcount drops on the fwnode. e.g., if we have two devices, A and B, with a connection, A -> B. If we remove B first, B would clear the reference on B, from A via coresight_remove_match(). But when A is removed, it still has a connection with fwnode still pointing to B. Thus it tries to drops the reference in coresight_release_platform_data(), raising the bells like : [ 91.990153] ------------[ cut here ]------------ [ 91.990163] refcount_t: addition on 0; use-after-free. [ 91.990212] WARNING: CPU: 0 PID: 461 at lib/refcount.c:25 refcount_warn_saturate+0xa0/0x144 [ 91.990260] Modules linked in: coresight_funnel coresight_replicator coresight_etm4x(-) crct10dif_ce coresight ip_tables x_tables ipv6 [last unloaded: coresight_cpu_debug] [ 91.990398] CPU: 0 PID: 461 Comm: rmmod Tainted: G W T 5.19.0-rc2+ #53 [ 91.990418] Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Feb 1 2019 [ 91.990434] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 91.990454] pc : refcount_warn_saturate+0xa0/0x144 [ 91.990476] lr : refcount_warn_saturate+0xa0/0x144 [ 91.990496] sp : ffff80000c843640 [ 91.990509] x29: ffff80000c843640 x28: ffff800009957c28 x27: ffff80000c8439a8 [ 91.990560] x26: ffff00097eff1990 x25: ffff8000092b6ad8 x24: ffff00097eff19a8 [ 91.990610] x23: ffff80000c8439a8 x22: 0000000000000000 x21: ffff80000c8439c2 [ 91.990659] x20: 0000000000000000 x19: ffff00097eff1a10 x18: ffff80000ab99c40 [ 91.990708] x17: 0000000000000000 x16: 0000000000000000 x15: ffff80000abf6fa0 [ 91.990756] x14: 000000000000001d x13: 0a2e656572662d72 x12: 657466612d657375 [ 91.990805] x11: 203b30206e6f206e x10: 6f69746964646120 x9 : ffff8000081aba28 [ 91.990854] x8 : 206e6f206e6f6974 x7 : 69646461203a745f x6 : 746e756f63666572 [ 91.990903] x5 : ffff00097648ec58 x4 : 0000000000000000 x3 : 0000000000000027 [ 91.990952] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff00080260ba00 [ 91.991000] Call trace: [ 91.991012] refcount_warn_saturate+0xa0/0x144 [ 91.991034] kobject_get+0xac/0xb0 [ 91.991055] of_node_get+0x2c/0x40 [ 91.991076] of_fwnode_get+0x40/0x60 [ 91.991094] fwnode_handle_get+0x3c/0x60 [ 91.991116] fwnode_get_nth_parent+0xf4/0x110 [ 91.991137] fwnode_full_name_string+0x48/0xc0 [ 91.991158] device_node_string+0x41c/0x530 [ 91.991178] pointer+0x320/0x3ec [ 91.991198] vsnprintf+0x23c/0x750 [ 91.991217] vprintk_store+0x104/0x4b0 [ 91.991238] vprintk_emit+0x8c/0x360 [ 91.991257] vprintk_default+0x44/0x50 [ 91.991276] vprintk+0xcc/0xf0 [ 91.991295] _printk+0x68/0x90 [ 91.991315] of_node_release+0x13c/0x14c [ 91.991334] kobject_put+0x98/0x114 [ 91.991354] of_node_put+0x24/0x34 [ 91.991372] of_fwnode_put+0x40/0x5c [ 91.991390] fwnode_handle_put+0x38/0x50 [ 91.991411] coresight_release_platform_data+0x74/0xb0 [coresight] [ 91.991472] coresight_unregister+0x64/0xcc [coresight] [ 91.991525] etm4_remove_dev+0x64/0x78 [coresight_etm4x] [ 91.991563] etm4_remove_amba+0x1c/0x2c [coresight_etm4x] [ 91.991598] amba_remove+0x3c/0x19c ---truncated---

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
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 6.4 7.8
Attack Vector Local Local
Attack Complexity High Low
Privileges Required High Low
User Interaction None None
Scope Unchanged Unchanged
Confidentiality Impact High High
Integrity Impact High High
Availability Impact High High

CVSS v3 Vector

Red Hat CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/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.

My product is listed as "Out of Support Scope". What does this mean?

When a product is listed as "Out of Support Scope", it means a vulnerability with the impact level assigned to this CVE is no longer covered by its current support lifecycle phase. The product has been identified to contain the impacted component, but analysis to determine whether it is affected or not by this vulnerability was not performed. The product should be assumed to be affected. Customers are advised to apply any mitigation options documented on this page, consider removing or disabling the impacted component, or upgrade to a supported version of the product that has an update available.