CVE-2026-98587

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

firewire: cdev: fix back-transition for iso resource auto client resource

The todo member of iso resource auto structure represents the state of the client resource and normally transitions in the following order:

ISO RES AUTO ALLOC -> ISO RES AUTO REALLOC -> ISO RES AUTO DEALLOC

However, concurrent access from the work item and the file descriptor release function can cause the state to transition backwards from ISO RES AUTO DEALLOC to ISO RES AUTO REALLOC.

Prevent the back-transition by checking the current state before updating it in the work item.