CVE-2026-53234
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk3th percentile - higher than 3% of all known CVEs
Summary
A use-after-free vulnerability was found in the IBM EMAC network driver for the Linux kernel during device removal. Using devm_register_netdev() caused delayed unregister_netdev(), leading to access to freed hardware resources by interrupt handlers.
Risk Assessment
An attacker could exploit the race window between resource release and actual network device unregistration, potentially causing a kernel panic or arbitrary code execution in kernel context.
Recommendation
Immediately update the Linux kernel to a version containing the fix that replaces devm_register_netdev() with manual register_netdev() and calls unregister_netdev() before hardware teardown.
Original NVD description (English source)
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