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:
<pre>
ISO_RES_AUTO_ALLOC -> ISO_RES_AUTO_REALLOC -> ISO_RES_AUTO_DEALLOC
</pre>
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.