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Linux KernelOperating system · Linux

CVE-2026-53234

HIGH · 7.8 CVSS v3.1 Published 2026-06-25
Fix available
A fix is available. Upgrade to 6.12.94 / 6.18.36 or later.
See remediation →
80/100
Remediation priority · High
Zero-click Patch available 8 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In the Linux kernel, the following vulnerability has been resolved: net: ibm: emac: Fix use-after-free during device removal The driver was using devm_register_netdev() which causes unregister_netdev() to be deferred until the devres cleanup phase, which runs after emac_remove() returns. This creates a use-after-free window where: 1. emac_remove() is called, which tears down hardware (cancels work, detaches modules, unregisters from MAL) 2. emac_remove() returns 3. devres cleanup runs and finally calls unregister_netdev() During step 3, the network stack might still process packets, triggering emac_irq(), emac_poll(), or other handlers that access now-freed hardware resources (dev->emacp, dev->mal, etc.). Fix this by replacing devm_register_netdev() with manual register_netdev() and calling unregister_netdev() at the beginning of emac_remove(), before any hardware teardown. This ensures the network device is fully stopped and unregistered before hardware resources are released. The change is safe because: - dev->ndev is assigned very early in probe (before any error paths that could bypass emac_remove) - platform_set_drvdata() is only called after successful registration, so emac_remove() only runs for fully registered devices - unregister_netdev() is idempotent and safe to call on any registered device

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The IBM emac network driver uses devm_register_netdev() which defers network device unregistration until after emac_remove() completes. This creates a use-after-free where the network stack can still reference freed hardware resources (dev->emacp, dev->mal) during the devres cleanup phase. The fix requires replacing devm_register_netdev() with manual register_netdev()/unregister_netdev() calls to ensure the device is fully unregistered before hardware teardown begins.

MitigationReplace devm_register_netdev() with direct register_netdev() and call unregister_netdev() at the start of emac_remove() before any hardware resource cleanup to prevent the network stack from accessing freed structures.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 6.12, < 6.12.94>= 6.13, < 6.18.36>= 6.19, < 7.0.13= 7.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify kernel version
    Run 'uname -r' or check /proc/version to obtain the running kernel version
    Affected if The version falls within >= 6.12 and < 6.12.94, OR >= 6.13 and < 6.18.36, OR >= 6.19 and < 7.0.13, OR equals 7.1
  2. Check if IBM emac driver is enabled
    Examine kernel configuration (config.gz or /boot/config-$(uname -r)) or list loaded modules for 'emac' or 'ibm_emac'
    Affected if The IBM emac network driver is compiled into the kernel or loaded as a module
  3. Verify driver uses devm_register_netdev
    Locate the IBM emac driver source code in the kernel tree and search for devm_register_netdev function call in the driver initialization
    Affected if The driver source code contains devm_register_netdev() instead of direct register_netdev()
  4. Confirm device registration timing issue
    Examine the emac_remove() function in the driver to verify that unregister_netdev() is not called before hardware resource cleanup (dev->emacp, dev->mal)
    Affected if The driver does not call unregister_netdev() at the start of emac_remove() before cleaning up hardware structures

A system is affected if it runs a vulnerable kernel version within the listed ranges and has the IBM emac driver enabled using devm_register_netdev() with deferred unregistration.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 6.12.94 / 6.18.36 / 7.0.13 or later
Fixed in 6.12.946.18.367.0.13
Vendor patch git.kernel.org →
Interim mitigation

Replace devm_register_netdev() with direct register_netdev() and call unregister_netdev() at the start of emac_remove() before any hardware resource cleanup to prevent the network stack from accessing freed structures.

Recommended fix High confidence

Upgrade to kernel 6.12.94, 6.18.36, or 7.0.14 (depending on your major version branch), or kernel 7.2+ if on 7.1

  1. Identify the current running kernel version using `uname -r`
  2. If running kernel 6.12.x and version < 6.12.94: Upgrade to kernel 6.12.94 or later
  3. If running kernel 6.13.x through 6.18.x and version < 6.18.36: Upgrade to kernel 6.18.36 or later
  4. If running kernel 6.19.x through 7.0.x and version < 7.0.13: Upgrade to kernel 7.0.14 or later
  5. If running kernel 7.1: Upgrade to kernel 7.2 or later
  6. After kernel upgrade, reboot the system to load the fixed kernel
Caveat Kernel upgrades may require matching system utilities and drivers; ensure compatibility with hardware before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Linux Kernel Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-53234 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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