In the Linux kernel, the following vulnerability has been resolved: net/mctp: publish the mctp_dev only after it is initialised mctp_add_dev() links… (CVE-2026-98812)

The vulnerability in the Linux kernel's net/mctp component occurred because mctp_add_dev() linked the new mctp_dev into dev->mctp_ptr before the mdev->dev pointer was assigned. This allowed readers to dereference a NULL net_device pointer, causing a null pointer dereference detected by KASAN. The fix involved changing the code to publish the mctp_dev object only after it is fully initialized, ensuring that __mctp_dev_get() running under rcu_read_lock() never observes mdev->dev as NULL.

This vulnerability could cause a kernel null pointer dereference, potentially leading to a kernel crash or denial of service. There is no indication of active exploitation in the wild or further impact such as privilege escalation in the provided data.

A fix has been implemented in the Linux kernel to address this issue by publishing the mctp_dev object only after full initialization. Users should update to the patched kernel version containing this fix. No additional mitigation steps are indicated.