Use After Free Affecting linux-qemu-melange package, versions <6.18.38-r0


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.13% (4th percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-LINUXQEMUMELANGE-17949741
  • published11 Jul 2026
  • disclosed25 Jun 2026

Introduced: 25 Jun 2026

NewCVE-2026-53234  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Chainguard linux-qemu-melange to version 6.18.38-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream linux-qemu-melange package and not the linux-qemu-melange package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

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

CVSS Base Scores

version 3.1