CVE-2026-74514

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

KVM: s390: pci: Fix memory accounting for pinned/unpinned pages

The accountmem() and unaccountmem() functions call getuid() which increments the reference count of struct userstruct on every invocation. But we don't decrement the count by calling freeuid(). It also accounted/unaccounted the pages against the current->mm. But its possible the unaccountmem() can be called from a different process context than the one that originally pinned the pages.

Let's fix this by storing the pinning process userstruct and mmstruct when accounting for pinned pages, and subsequently free these resources when the pages are unpinned.

[borntraeger@linux.ibm.com: Fixed whitespace]