In the Linux kernel, the following vulnerability has been resolved: KVM: s390: pci: Fix memory accounting for pinned/unpinned pages The account_mem() and unaccount_mem() functions call get_uid() which increments the reference count of struct user_struct on every invocation. But we don't decrement the count by calling free_uid(). It also accounted/unaccounted the pages against the current->mm. But its possible the unaccount_mem() 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 user_struct and mm_struct when accounting for pinned pages, and subsequently free these resources when the pages are unpinned. [[email protected]: Fixed whitespace]
https://git.kernel.org/stable/c/e3f732e086e438c52c7400bd2734bb166aa4752c
https://git.kernel.org/stable/c/70871b121f81d08879363cb1238a4c85c5c2800c
https://git.kernel.org/stable/c/36f6999ecde3976731a8bfc0b8e667da6f593069