CVE-2026-53234
Analyzed
Analyzed - Analysis Complete
Use-After-Free in IBM EMAC Linux Kernel Driver
Vulnerability report for CVE-2026-53234, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-06-25
Last updated on: 2026-07-08
Assigner: kernel.org
Description
Description
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 Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | 7.1 |
| linux | linux_kernel | 7.1 |
| linux | linux_kernel | 7.1 |
| linux | linux_kernel | 7.1 |
| linux | linux_kernel | From 6.13 (inc) to 6.18.36 (exc) |
| linux | linux_kernel | From 6.19 (inc) to 7.0.13 (exc) |
| linux | linux_kernel | 7.1 |
| linux | linux_kernel | 7.1 |
| linux | linux_kernel | 7.1 |
| linux | linux_kernel | From 6.12 (inc) to 6.12.94 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-416 | The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. |
