CVE-2021-47235: net: ethernet: fix potential use-after-free in ec_bhf_remove

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-05-21 · updated 2026-06-17
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: net: ethernet: fix potential use-after-free in ec_bhf_remove static void ec_bhf_remove(struct pci_dev *dev) { ... struct ec_bhf_priv *priv = netdev_priv(net_dev); unregister_netdev(net_dev); free_netdev(net_dev); pci_iounmap(dev, priv->dma_io); pci_iounmap(dev, priv->io); ... } priv is netdev private data, but it is used after free_netdev(). It can cause use-after-free when accessing priv pointer. So, fix it by moving free_netdev() after pci_iounmap() calls.

Affected products

Linux kernel: from 3.15 before 4.4.274; from 4.5 before 4.9.274; from 4.10 before 4.14.238; from 4.15 before 4.19.196; from 4.20 before 5.4.128; from 5.5 before 5.10.46 — fixed in 4.14.238, 4.19.196, 4.4.274, 4.9.274, 5.10.46, 5.12.13

How to fix

Upgrade to a fixed version: Linux kernel 4.14.238, 4.19.196, 4.4.274, 4.9.274. Check the vendor advisory for mitigations.

References

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