CVE-2026-98008: Linux Vulnerability

Description

In the Linux kernel, the following vulnerability has been resolved: net: macb: fix NULL pointer dereference on unbind with fixed-link When the device tree describes a fixed-link and has no "mdio" child node, macb_mii_init() returns early without allocating the MDIO bus, leaving bp->mii_bus as NULL. Two cleanup paths then dereference this NULL bus: 1. On driver unbind, macb_remove() unconditionally calls mdiobus_unregister(bp->mii_bus), which oopses: Unable to handle kernel NULL pointer dereference at virtual address 00000000000004a8 pc : mdiobus_unregister+0x14/0xa4 lr : macb_remove+0x38/0xa4 Call trace: mdiobus_unregister+0x14/0xa4 (P) macb_remove+0x38/0xa4 platform_remove+0x20/0x30 device_release_driver_internal+0x1c8/0x224 unbind_store+0xb4/0xbc 2. On the probe error path in macb_probe(), reached when macb_mii_init() has succeeded but a subsequent step fails, the err_out_unregister_mdio label runs the same unconditional cleanup. mdiobus_unregister() and mdiobus_free() do not guard against a NULL bus, so guard the calls in both macb_remove() and the probe error path.

Metrics

EPSS Probability

0.17%

6.2th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= 831e19e565b5210930fa183730071f8290c61263, < afa224cabc0132ca414b9141b1a919ca2d318cd0; >= 81db1e52848694761a1aa162ce76198af9964ed8, < 054ad8e66025eb4778d840bef80c270646cebcd2; >= d0c3601f2c4e12e7689b0f46ebc17525250ea8c3, < f737d999fcb8f276d77b01ea4c2016ee01dad19b; >= d0c3601f2c4e12e7689b0f46ebc17525250ea8c3, < 5710f6a74f63cbba0e15cd75917234916181c9d4; >= d0c3601f2c4e12e7689b0f46ebc17525250ea8c3, < edb39c7666bb3924da761dfb417db85c1e5d8ad3; >= d0c3601f2c4e12e7689b0f46ebc17525250ea8c3, < 38b6be101006d3e7af972999f45d4f1e8250587a; cafa5942bd2df3d80e3eeb2deb4bc050f7761f3d; c81dcaa9cd0b66816c2ecb6c5df0b6afde9c7da5; 19088c5378c9fea54e552d8bc7418a3aa1e06990; >= 6.1.114, < 6.1.189; >= 6.6.58, < 6.6.158; >= 5.10.228, < 5.11; >= 5.15.169, < 5.16; >= 6.11.5, < 6.12
Linux	Linux	6.12

References

Timeline

Published: Sep 25, 2026
Last Modified: Oct 19, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-98008?

In the Linux kernel, the following vulnerability has been resolved: net: macb: fix NULL pointer dereference on unbind with fixed-link When the device tree describes a fixed-link and has no "mdio" child node, macb_mii_init() returns early without allocating the MDIO bus, leaving bp->mii_bus as NULL. Two cleanup paths then dereference this NULL bus: 1. On driver unbind, macb_remove() unconditionally calls mdiobus_unregister(bp->mii_bus), which oopses: Unable to handle kernel NULL pointer dereference at virtual address 00000000000004a8 pc : mdiobus_unregister+0x14/0xa4 lr : macb_remove+0x38/0xa4 Call trace: mdiobus_unregister+0x14/0xa4 (P) macb_remove+0x38/0xa4 platform_remove+0x20/0x30 device_release_driver_internal+0x1c8/0x224 unbind_store+0xb4/0xbc 2. On the probe error path in macb_probe(), reached when macb_mii_init() has succeeded but a subsequent step fails, the err_out_unregister_mdio label runs the same unconditional cleanup. mdiobus_unregister() and mdiobus_free() do not guard against a NULL bus, so guard the calls in both macb_remove() and the probe error path.

How severe is CVE-2026-98008?

Severity scoring for CVE-2026-98008 is pending analysis. The EPSS model estimates a 0.17% probability of exploitation in the next 30 days.

How do I fix CVE-2026-98008?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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