In the Linux kernel, the following vulnerability has been resolved: USB: serial: fix port tear down use-after-free Some drivers for multiport… (CVE-2026-98772)

The vulnerability in the Linux kernel USB serial subsystem affects some multiport device drivers that access port driver data from completion handlers of shared URBs. Although a NULL check prevents access to unallocated port state containers, a race condition exists where a completion handler can access freed driver data during port teardown. The resolution reorders the disconnect process so that ports are only deregistered and their driver data freed after all ports have been hung up and the disconnect callback has run, ensuring all I/O has stopped before freeing resources.

This use-after-free vulnerability could lead to kernel memory corruption or crashes if a completion handler accesses freed memory during port teardown. The impact is limited to affected USB serial multiport drivers in the Linux kernel. No known exploits in the wild have been reported.

A fix has been implemented in the Linux kernel to reorder the disconnect handling process to prevent use-after-free conditions. Users should apply the official kernel updates that include this fix. Patch status is not explicitly confirmed in the provided data; check the vendor advisory or Linux kernel mailing lists for the specific patch and update guidance.