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.
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||||||||||||||||||||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
Sign in to view the affected projects.
No advisories yet.
Fri, 25 Sep 2026 17:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-476 |
Fri, 25 Sep 2026 10:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | net: macb: fix NULL pointer dereference on unbind with fixed-link | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-25T10:23:33.532Z
Reserved: 2026-09-25T10:19:56.068Z
Link: CVE-2026-98008
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-25T11:17:29.080
Modified: 2026-09-25T11:17:29.080
Link: CVE-2026-98008
Redhat
No data.
OpenCVE Enrichment
Updated: 2026-09-25T16:45:08Z
-
CWE-476
NULL Pointer Dereference