CVE-2026-68403 wifi: brcmfmac: initialize SDIO data work before cleanup

Not scored Published 10 Aug 2026 Updated 19 Aug 2026

A flaw in the Linux kernel brcmfmac Wi-Fi driver allows a local attacker to cause a denial of service via a null pointer dereference during device initialization failure.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2026-68403?

CVE-2026-68403 is a vulnerability in Linux, published on 10 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

wifi: brcmfmac: initialize SDIO data work before cleanup

brcmf_sdio_probe() stores the newly allocated bus in sdiodev->bus before allocating the ordered workqueue. If that allocation fails, the function jumps to fail and calls brcmf_sdio_remove().

brcmf_sdio_remove() unconditionally cancels bus->datawork. Initialize the work item before the first failure path that can reach brcmf_sdio_remove(), so the cleanup path always observes a valid work object.

This issue was found by our static analysis tool and then confirmed by manual review of the probe error path and the remove-time work drain. The problem pattern is an early setup failure that reaches a cleanup helper which cancels an embedded work item before its initializer has run.

A QEMU PoC forced alloc_ordered_workqueue() to fail at the same point in brcmf_sdio_probe(), before INIT_WORK(&bus->datawork) is reached. The resulting fail path calls brcmf_sdio_remove(), and DEBUG_OBJECTS reports the invalid work drain with brcmf_sdio_probe() and brcmf_sdio_remove() in the stack.

Which versions are affected by CVE-2026-68403?

How do I fix CVE-2026-68403?

Apply the vendor's patch.

Is CVE-2026-68403 being exploited?

There is no known exploitation of CVE-2026-68403 in the wild and no public exploit code.

Sources

Also known as BELL-CVE-2026-68403, DEBIAN-CVE-2026-68403, GHSA-2jx9-wxwh-fv4q, UBUNTU-CVE-2026-68403.