CVE-2025-39976

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

futex: Use correct exit on failure from futexhashallocate_default()

copyprocess() uses the wrong error exit path from futexhashallocatedefault(). After exiting from futexhashallocatedefault(), neither tasklistlock nor siglock has been acquired. The exit label badforkcore_free unlocks both of these locks which is wrong.

The next exit label, badforkcancelcgroup, is the correct exit. schedcgroup_fork() did not allocate any resources that need to freed.

Use badforkcancelcgroup on error exit from futexhashallocatedefault().